message stringlengths 2 23.8k | message_type stringclasses 2 values | message_id int64 0 1 | conversation_id int64 97 109k | cluster float64 0 0 | __index_level_0__ int64 194 217k |
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Provide a correct Python 3 solution for this coding contest problem.
Problem J String Puzzle
Amazing Coding Magazine is popular among young programmers for its puzzle solving contests offering catchy digital gadgets as the prizes. The magazine for programmers naturally encourages the readers to solve the puzzles by writing programs. Let's give it a try!
The puzzle in the latest issue is on deciding some of the letters in a string (the secret string, in what follows) based on a variety of hints. The figure below depicts an example of the given hints.
<image>
The first hint is the number of letters in the secret string. In the example of the figure above, it is nine, and the nine boxes correspond to nine letters. The letter positions (boxes) are numbered starting from 1, from the left to the right.
The hints of the next kind simply tell the letters in the secret string at some speci c positions. In the example, the hints tell that the letters in the 3rd, 4th, 7th, and 9th boxes are C, I, C, and P
The hints of the final kind are on duplicated substrings in the secret string. The bar immediately below the boxes in the figure is partitioned into some sections corresponding to substrings of the secret string. Each of the sections may be connected by a line running to the left with another bar also showing an extent of a substring. Each of the connected pairs indicates that substrings of the two extents are identical. One of this kind of hints in the example tells that the letters in boxes 8 and 9 are identical to those in boxes 4 and 5, respectively. From this, you can easily deduce that the substring is IP.
Note that, not necessarily all of the identical substring pairs in the secret string are given in the hints; some identical substring pairs may not be mentioned.
Note also that two extents of a pair may overlap each other. In the example, the two-letter substring in boxes 2 and 3 is told to be identical to one in boxes 1 and 2, and these two extents share the box 2.
In this example, you can decide letters at all the positions of the secret string, which are "CCCIPCCIP". In general, the hints may not be enough to decide all the letters in the secret string.
The answer of the puzzle should be letters at the specified positions of the secret string. When the letter at the position specified cannot be decided with the given hints, the symbol ? should be answered.
Input
The input consists of a single test case in the following format.
$n$ $a$ $b$ $q$
$x_1$ $c_1$
...
$x_a$ $c_a$
$y_1$ $h_1$
...
$y_b$ $h_b$
$z_1$
...
$z_q$
The first line contains four integers $n$, $a$, $b$, and $q$. $n$ ($1 \leq n \leq 10^9$) is the length of the secret string, $a$ ($0 \leq a \leq 1000$) is the number of the hints on letters in specified positions, $b$ ($0 \leq b \leq 1000$) is the number of the hints on duplicated substrings, and $q$ ($1 \leq q \leq 1000$) is the number of positions asked.
The $i$-th line of the following a lines contains an integer $x_i$ and an uppercase letter $c_i$ meaning that the letter at the position $x_i$ of the secret string is $c_i$. These hints are ordered in their positions, i.e., $1 \leq x_1 < ... < x_a \leq n$.
The $i$-th line of the following $b$ lines contains two integers, $y_i$ and $h_i$. It is guaranteed that they satisfy $2 \leq y_1 < ... < y_b \leq n$ and $0 \leq h_i < y_i$. When $h_i$ is not 0, the substring of the secret string starting from the position $y_i$ with the length $y_{i+1} - y_i$ (or $n+1-y_i$ when $i = b$) is identical to the substring with the same length starting from the position $h_i$. Lines with $h_i = 0$ does not tell any hints except that $y_i$ in the line indicates the end of the substring specified in the line immediately above.
Each of the following $q$ lines has an integer $z_i$ ($1 \leq z_i \leq n$), specifying the position of the letter in the secret string to output.
It is ensured that there exists at least one secret string that matches all the given information. In other words, the given hints have no contradiction.
Output
The output should be a single line consisting only of $q$ characters. The character at position $i$ of the output should be the letter at position $z_i$ of the the secret string if it is uniquely determined from the hints, or ? otherwise.
Sample Input 1
9 4 5 4
3 C
4 I
7 C
9 P
2 1
4 0
6 2
7 0
8 4
8
1
9
6
Sample Output 1
ICPC
Sample Input 2
1000000000 1 1 2
20171217 A
3 1
42
987654321
Sample Output 2
?A
Example
Input
9 4 5 4
3 C
4 I
7 C
9 P
2 1
4 0
6 2
7 0
8 4
8
1
9
6
Output
ICPC | instruction | 0 | 47,893 | 0 | 95,786 |
"Correct Solution:
```
from bisect import bisect
n, a, b, q = map(int, input().split())
W = [input().split() for i in range(a)]
X = [int(x) for x, c in W]
C = [c for x, c in W]
P = [list(map(int, input().split())) for i in range(b)]
Y = [y for y, h in P] + [n+1]
D = [0]*b
for i in range(b):
y0, h = P[i]; y1 = Y[i+1]
D[i] = min(y0 - h, y1 - y0)
idx = 0
S = {}
for i in range(a):
x = X[i]; c = C[i]
S[x] = c
if x < Y[0]:
continue
while Y[idx+1] <= x: idx += 1
i = idx
while Y[0] <= x:
while x < Y[i]: i -= 1
y0, h = P[i]
if h == 0: break
x = h + ((x - y0) % D[i])
S[x] = c
def check(z):
if z in S:
return S[z]
i = bisect(Y, z)-1
while Y[0] <= z:
while z < Y[i]: i -= 1
y0, h = P[i]
if h == 0: break
z = h + ((z - y0) % D[i])
if z in S:
return S[z]
return '?'
Z = (int(input()) for i in range(q))
print(*map(check, Z), sep='')
``` | output | 1 | 47,893 | 0 | 95,787 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,968 | 0 | 95,936 |
Tags: brute force, implementation, strings
Correct Solution:
```
n,k=map(int,input().split())
s=input()
s=s+'\0'
s2=set(s)
max=0
dic={}
count=0
for i in range(n):
count=count+1
if s[i]!=s[i+1]:
if s[i] in dic:
dic[s[i]]=dic[s[i]]+count//k
else:
dic[s[i]]=count//k
count=0
for i in dic:
if dic[i]>max:
max=dic[i]
print(max)
``` | output | 1 | 47,968 | 0 | 95,937 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,969 | 0 | 95,938 |
Tags: brute force, implementation, strings
Correct Solution:
```
s1 = input().split()
n = int(s1[0])
k = int(s1[1])
string = input()
estimc = string[0]
cnt = 0
lit = dict({estimc:0})
for c in string:
if(c == estimc):
cnt+=1
if(cnt == k):
cnt = 0
if(estimc in lit):
lit[estimc] +=1
else:
lit[estimc] = 1
else:
cnt = 1
estimc = c
print(max(lit.values()))
``` | output | 1 | 47,969 | 0 | 95,939 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,970 | 0 | 95,940 |
Tags: brute force, implementation, strings
Correct Solution:
```
n,k= map(int,input().split())
s = list(input())
l = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x',"y","z"]
ma =0
for i in l:
t=0
c=0
te =s[0]
for j in s:
if(j==i):
c=c+1
else:
c=0
if(c==k):
c=0
t+=1
if(t>ma):
ma= t
print(ma)
``` | output | 1 | 47,970 | 0 | 95,941 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,971 | 0 | 95,942 |
Tags: brute force, implementation, strings
Correct Solution:
```
from collections import defaultdict as dd
n, k=map(int,input().split())
s=input()
res=dd(int)
pr=s[0]
cc=1
for c in s[1:]:
if c == pr:
cc+=1
else:
res[pr] += cc//k
pr = c
cc=1
res[pr]+=cc//k
print(max(res.values()))
``` | output | 1 | 47,971 | 0 | 95,943 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,972 | 0 | 95,944 |
Tags: brute force, implementation, strings
Correct Solution:
```
x=[int(s) for s in input().split()]
y=x[1]
s=input()
r=[]
c=1
m=0
d="_"
for i in s:
if i==d:
c+=1
elif d=="_":
d=i
else:
r.append((c,d))
c=1
d=i
r.append((c,d))
for i in "abcdefghijklmnopqrstuvwxyz":
tm=0
for f,l in r:
if f>=y and i==l:
tm+=f//y
m=max(m,tm)
print(m)
``` | output | 1 | 47,972 | 0 | 95,945 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,973 | 0 | 95,946 |
Tags: brute force, implementation, strings
Correct Solution:
```
n, k = map(int, input().split())
s = input()
prev = s[0]
d = {}
count = 1
for i in range(1, n):
if s[i] == prev:
count += 1
else:
if not d.get(prev):
d[prev] = [count]
else:
d[prev].append(count)
count = 1
prev = s[i]
if not d.get(prev):
d[prev] = [count]
else:
d[prev].append(count)
count = 1
prev = s[i]
result = 0
for key in d.keys():
count = 0
for x in d[key]:
count += x//k
result = max(result, count)
print(result)
``` | output | 1 | 47,973 | 0 | 95,947 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,974 | 0 | 95,948 |
Tags: brute force, implementation, strings
Correct Solution:
```
k = int(input().split()[1])
result = {}
prev = 0
value = 0
STR = input() + '$'
for letter in STR:
if letter != prev:
result[prev] = result.get(prev, 0) + value//k
prev = letter
value = 0
value+=1
print(max(result.values()))
``` | output | 1 | 47,974 | 0 | 95,949 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1. | instruction | 0 | 47,975 | 0 | 95,950 |
Tags: brute force, implementation, strings
Correct Solution:
```
def check(s,i,k):
for j in range(i+1,i+k):
if s[j]!=s[i]:
return j
return None
n,k=map(int,input().split())
s=input()
i=0
l=[0]*26
while i<n-k+1:
if check(s,i,k)==None:
l[ord(s[i])-97]+=1
i+=k
else:
i=check(s,i,k)
if len(l)!=0:
print(max(l))
else:
print(0)
``` | output | 1 | 47,975 | 0 | 95,951 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
n,k=map(int,input().split())
s=input()
d={}
i=0
m=0
while i<len(s):
flag=False
x=s[i:k+i]
if len(x)!=k:
break
for z in range(len(x)):
if x[z]!=x[-1]:
i+=z
flag=True
break
if not flag:
if x[-1] in d:
d[x[-1]]+=1
else:
d[x[-1]]=1
i+=k-1
i+=1
for i in d:
if d[i[-1]]>m:
m=d[i[-1]]
#print(s)
print(m)
``` | instruction | 0 | 47,976 | 0 | 95,952 |
Yes | output | 1 | 47,976 | 0 | 95,953 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
from collections import Counter
n,k=map(int,input().split())
s=input()
s+="%"
s=[i for i in s]
#print(s)
local=0
d={}
if n==1 and k==1:
print(1)
elif n==1 and k>1:
print(0)
else:
for i in s:
d[i]=0
for i in range(len(s)-1):
if s[i]==s[i+1]:
local+=1
else:
d[s[i]]+=(local+1)//k
local=0
d[s[-1]]+=(local+1)//k
del d['%']
#print(d)
print(max(d.values()))
``` | instruction | 0 | 47,977 | 0 | 95,954 |
Yes | output | 1 | 47,977 | 0 | 95,955 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
k=int(input().split()[1])
d={}
p=l=0
for c in input()+'#':
if c!=p:d[p]=d.get(p,0)+l//k;l=0;p=c
l+=1
print(max(d.values()))
``` | instruction | 0 | 47,978 | 0 | 95,956 |
Yes | output | 1 | 47,978 | 0 | 95,957 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
l,k=map(int,input().split())
s=input()
c=[None]*26
for i in range(26):
c[i]=[]
a=1
for i in range(1,l):
if s[i]!=s[i-1]:
c[ord(s[i-1])-ord('a')].append(a)
a=1
else:
a+=1
c[ord(s[l-1]) - ord('a')].append(a)
ans=0
for i in range(26):
cumm=0
for j in c[i]:
cumm+=j//k
ans=max(ans,cumm)
print(ans)
``` | instruction | 0 | 47,979 | 0 | 95,958 |
Yes | output | 1 | 47,979 | 0 | 95,959 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
n, k = [int(s) for s in input().split()]
s = input()
counter = 1
dict = {"fictive":0}
if n == 1 and k == 1:
print(1)
else:
i = 1
while i < len(s):
if s[i] == s[i-1]:
counter += 1
else:
counter = 1
if counter == k:
dict[s[i]*k] = dict.get(s[i]*k, 0) + 1
counter = 1
i += 1
i += 1
print(max(dict.values()))
``` | instruction | 0 | 47,980 | 0 | 95,960 |
No | output | 1 | 47,980 | 0 | 95,961 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
n, k = map(int, input().split())
s = input()
a, b = {}, {}
for i in range(0,n,k):
if len(set(s[i:i+k])) == 1:
a[s[i]] = a.get(s[i], 0) + 1
t1 = 0
for i in a.keys():
if a[i] > t1: t1 = a[i]
print(t1)
``` | instruction | 0 | 47,981 | 0 | 95,962 |
No | output | 1 | 47,981 | 0 | 95,963 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
from collections import Counter
n,k=input().split()
n=int(n)
k=int(k)
s=input()
net_count=[]
j=0
i=0
while(j<=(k)):
x=[]
i=j
while(i<(n)):
x.append(s[i:i+k])
i=i+k
j+=1
final=dict(Counter(x))
new1=list(final)
new2=list(final.values())
flag=0
for i in range(len(new1)):
if(len(set(new1[i]))==1 and len(new1[i])==k):
flag=1
net_count.append(new2[i])
break
if(flag==0):
net_count.append(0)
print(max(net_count))
``` | instruction | 0 | 47,982 | 0 | 95,964 |
No | output | 1 | 47,982 | 0 | 95,965 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string s of length n and integer k (1 ≤ k ≤ n). The string s has a level x, if x is largest non-negative integer, such that it's possible to find in s:
* x non-intersecting (non-overlapping) substrings of length k,
* all characters of these x substrings are the same (i.e. each substring contains only one distinct character and this character is the same for all the substrings).
A substring is a sequence of consecutive (adjacent) characters, it is defined by two integers i and j (1 ≤ i ≤ j ≤ n), denoted as s[i ... j] = "s_{i}s_{i+1} ... s_{j}".
For example, if k = 2, then:
* the string "aabb" has level 1 (you can select substring "aa"),
* the strings "zzzz" and "zzbzz" has level 2 (you can select two non-intersecting substrings "zz" in each of them),
* the strings "abed" and "aca" have level 0 (you can't find at least one substring of the length k=2 containing the only distinct character).
Zuhair gave you the integer k and the string s of length n. You need to find x, the level of the string s.
Input
The first line contains two integers n and k (1 ≤ k ≤ n ≤ 2 ⋅ 10^5) — the length of the string and the value of k.
The second line contains the string s of length n consisting only of lowercase Latin letters.
Output
Print a single integer x — the level of the string.
Examples
Input
8 2
aaacaabb
Output
2
Input
2 1
ab
Output
1
Input
4 2
abab
Output
0
Note
In the first example, we can select 2 non-intersecting substrings consisting of letter 'a': "(aa)ac(aa)bb", so the level is 2.
In the second example, we can select either substring "a" or "b" to get the answer 1.
Submitted Solution:
```
from collections import Counter
n,k=map(int,input().split())
s=input()
check=dict(Counter(s))
step=0
level=1
for i in range(n-1):
if s[i]==s[i+1]:
level+=1
else:
if level>=k:
step+=1
level=1
print(step)
``` | instruction | 0 | 47,983 | 0 | 95,966 |
No | output | 1 | 47,983 | 0 | 95,967 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,083 | 0 | 96,166 |
Tags: constructive algorithms, strings
Correct Solution:
```
T = int(input().rstrip())
for test in range(T):
n = int(input().rstrip())
input_str = input().rstrip()
foo = ""
for idx in range(len(input_str)):
if idx % 2 == 0:
foo = foo + input_str[idx]
print(foo)
``` | output | 1 | 48,083 | 0 | 96,167 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,084 | 0 | 96,168 |
Tags: constructive algorithms, strings
Correct Solution:
```
def main():
t = int(input())
while t:
n = int(input())
s = input()
ans = ""
i = 0
while i < 2 * n - 1:
ans += s[i]
i += 2
print(ans)
t -= 1
if __name__ == "__main__":
main()
``` | output | 1 | 48,084 | 0 | 96,169 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,085 | 0 | 96,170 |
Tags: constructive algorithms, strings
Correct Solution:
```
t = int(input())
while t:
n = int(input())
inp = str(input())
print(inp[::2])
t -= 1
``` | output | 1 | 48,085 | 0 | 96,171 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,086 | 0 | 96,172 |
Tags: constructive algorithms, strings
Correct Solution:
```
t=input()
t=int(t)
while(t>0):
n=input()
s=input()
d=1
for i in s:
if(d%2!=0):
print(i,end="")
d=d+1;
t=t-1
print()
``` | output | 1 | 48,086 | 0 | 96,173 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,087 | 0 | 96,174 |
Tags: constructive algorithms, strings
Correct Solution:
```
t = int(input())
A = []
B = []
C = []
for i in range(t):
n = int(input())
s = input()
B = ["1" for j in range(n)]
C = ["0" for j in range(n)]
one = "".join(B)
zero = "".join(C)
if s.find(one) != -1:
A.append(one)
elif s.find(zero) != -1:
A.append(zero)
else:
A.append(one)
for i in A:
print(i)
``` | output | 1 | 48,087 | 0 | 96,175 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,088 | 0 | 96,176 |
Tags: constructive algorithms, strings
Correct Solution:
```
n = int(input())
for _ in range(n):
k = int(input())
s = input()
print(s[k - 1]*k)
``` | output | 1 | 48,088 | 0 | 96,177 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,089 | 0 | 96,178 |
Tags: constructive algorithms, strings
Correct Solution:
```
t = int(input())
while t:
n = int(input())
s = input()
l = []
j = 1
ans = ""
for i in range(1, n + 1):
l.append(s[i - 1 : n])
n += 1
ans += l[0][0]
for i in l[1:]:
ans += i[j]
j += 1
print(ans)
t -= 1
``` | output | 1 | 48,089 | 0 | 96,179 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01. | instruction | 0 | 48,090 | 0 | 96,180 |
Tags: constructive algorithms, strings
Correct Solution:
```
import sys
input = sys.stdin.readline
t = int(input().strip())
## first read everything
inputs = []
for i in range(0, t):
n = int(input().strip())
s = input()
inputs.append([n, s])
for i in range(0, t):
# read both lines
n = inputs[i][0]
s = inputs[i][1]
similar = s[0]
## construct similar:
# the moving window:
for j in range(1, n):
has_similar = False
last_letter_to_traverse = j + len(similar)
pos = j
while pos < last_letter_to_traverse and not has_similar:
if s[pos] == similar[pos-j]:
has_similar = True
else:
pos += 1
if not has_similar and len(similar) < n:
# add new
similar += s[pos]
while len(similar) < n:
similar += '0'
print(similar)
``` | output | 1 | 48,090 | 0 | 96,181 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
def incrementaResp(s, n):
for i in range(n-1, -1, -1):
if s[i]=='0':
s[i]='1'
break
else:
s[i]='0'
t = int(input())
for testCase in range(t):
n = int(input())
s1 = input()
s2 = ["0"]*(2*n-1)
for i in range(len(s1)):
if s1[i]=="0":
s2[i]="1"
resp = ["0"]*n
while True:
if "".join(resp) in "".join(s2):
incrementaResp(resp, n)
else:
break
for e in resp:
print(e, end='')
print()
``` | instruction | 0 | 48,091 | 0 | 96,182 |
Yes | output | 1 | 48,091 | 0 | 96,183 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
n=int(input())
for i in range(n):
t=int(input())
s=input()
if len(s)==1:
print(s)
else:
ans=[]
if len(s)%2!=0:
for i in range(0,len(s),2):
ans.append(s[i])
for i in ans:
print(str(i),end='')
print()
``` | instruction | 0 | 48,092 | 0 | 96,184 |
Yes | output | 1 | 48,092 | 0 | 96,185 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
import sys
from collections import defaultdict as dd
from collections import Counter as cc
from queue import Queue
import math
import itertools
try:
sys.stdin = open('input.txt', 'r')
sys.stdout = open('output.txt', 'w')
except:
pass
# input = lambda: sys.stdin.buffer.readline().rstrip()
for _ in range(int(input())):
q=int(input())
w=input()
k=''
for i in range(0,2*q-1,2):
k+=w[i]
print(k)
``` | instruction | 0 | 48,093 | 0 | 96,186 |
Yes | output | 1 | 48,093 | 0 | 96,187 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
T = int(input())
for _ in range(T):
N = int(input())
s = input()
res = ''
for i in range(0, len(s), 2):
res += s[i]
print(res)
``` | instruction | 0 | 48,094 | 0 | 96,188 |
Yes | output | 1 | 48,094 | 0 | 96,189 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
import sys
input = sys.stdin.readline
T = int(input())
for t in range(T):
N = int(input())
s = input()[:-1]
if s[N-1] == '1':
print('1'*(2*N-1))
else:
print('0'*(2*N-1))
``` | instruction | 0 | 48,095 | 0 | 96,190 |
No | output | 1 | 48,095 | 0 | 96,191 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
t = int(input())
for _ in range(t):
n = int(input())
s = input()
ans = [1]*(n-1)
ans += s[n-1]
print(*ans, sep='')
``` | instruction | 0 | 48,096 | 0 | 96,192 |
No | output | 1 | 48,096 | 0 | 96,193 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
t=int(input())
for i in range(t):
n=int(input())
s=input()
if(n>2):
print(s[ :n])
if(n==1):
print(s)
if(n==2):
print(s[0],end="")
print(s[n])
``` | instruction | 0 | 48,097 | 0 | 96,194 |
No | output | 1 | 48,097 | 0 | 96,195 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:
* 10010 and 01111 are similar (they have the same character in position 4);
* 10010 and 11111 are similar;
* 111 and 111 are similar;
* 0110 and 1001 are not similar.
You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).
You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].
Input
The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.
The first line of each test case contains a single integer n (1 ≤ n ≤ 50).
The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.
Output
For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.
Example
Input
4
1
1
3
00000
4
1110000
2
101
Output
1
000
1010
00
Note
The explanation of the sample case (equal characters in equal positions are bold):
The first test case:
* 1 is similar to s[1..1] = 1.
The second test case:
* 000 is similar to s[1..3] = 000;
* 000 is similar to s[2..4] = 000;
* 000 is similar to s[3..5] = 000.
The third test case:
* 1010 is similar to s[1..4] = 1110;
* 1010 is similar to s[2..5] = 1100;
* 1010 is similar to s[3..6] = 1000;
* 1010 is similar to s[4..7] = 0000.
The fourth test case:
* 00 is similar to s[1..2] = 10;
* 00 is similar to s[2..3] = 01.
Submitted Solution:
```
import sys,math
input=sys.stdin.readline
t=int(input())
for r in range(t):
n = int(input())
s = input().strip("\n")
print(s[:n])
``` | instruction | 0 | 48,098 | 0 | 96,196 |
No | output | 1 | 48,098 | 0 | 96,197 |
Provide a correct Python 3 solution for this coding contest problem.
Let N be a positive integer. You are given a string s of length N - 1, consisting of `<` and `>`.
Find the number of permutations (p_1, p_2, \ldots, p_N) of (1, 2, \ldots, N) that satisfy the following condition, modulo 10^9 + 7:
* For each i (1 \leq i \leq N - 1), p_i < p_{i + 1} if the i-th character in s is `<`, and p_i > p_{i + 1} if the i-th character in s is `>`.
Constraints
* N is an integer.
* 2 \leq N \leq 3000
* s is a string of length N - 1.
* s consists of `<` and `>`.
Input
Input is given from Standard Input in the following format:
N
s
Output
Print the number of permutations that satisfy the condition, modulo 10^9 + 7.
Examples
Input
4
<><
Output
5
Input
5
<<<<
Output
1
Input
20
>>>><>>><>><>>><<>>
Output
217136290 | instruction | 0 | 48,607 | 0 | 97,214 |
"Correct Solution:
```
N=int(input())
S=input()
mod=10**9+7
#DP[i]#最後においた数の右にある残っている個数
rest=N-1
DP=[1]*(N)
for s in S:
NDP=[0]*(N)
if s=="<":
for i in range(rest+1):
if i>=1:
NDP[i-1]=(DP[i]+NDP[i-1])%mod
DP=NDP
for i in range(N-2,-1,-1):
DP[i]=(DP[i+1]+DP[i])%mod
else:
DP=[DP[rest-i] for i in range(N)]#左右逆にして考える
#print(DP)
for i in range(rest+1):
if i>=1:
NDP[i-1]=(DP[i]+NDP[i-1])%mod
DP=NDP
for i in range(N-2,-1,-1):
DP[i]=(DP[i+1]+DP[i])%mod
DP=[DP[rest-1-i] for i in range(N)]
rest-=1
#print(DP,rest)
print(DP[0])
``` | output | 1 | 48,607 | 0 | 97,215 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,638 | 0 | 97,276 |
"Correct Solution:
```
def count_inversions(L):
def helper(A,B):
lA,lB = len(A),len(B)
if lA == 0:
return B,0
elif lB == 0:
return A,0
A,c1 = helper(A[:lA//2],A[lA//2:])
B,c2 = helper(B[:lB//2],B[lB//2:])
cnt = c1+c2
i = 0
j = 0
C = [None]*(lA+lB)
while i < lA and j < lB:
if A[i] > B[j]:
cnt += lA-i
C[i+j] = B[j]
j += 1
else:
C[i+j] = A[i]
i += 1
if i < lA:
C[i+j:] = A[i:]
else:
C[i+j:] = B[j:]
return C,cnt
return helper(L[:len(L)//2],L[len(L)//2:])[1]
from collections import deque
ALPHABETS = 26
indices = [deque() for _ in range(26)]
S = list(map(lambda c: ord(c)-ord('a'),input()))
for i,c in enumerate(S):
indices[c] += [i]
odd = None
for c,l in enumerate(indices):
if len(l)%2 == 1:
if odd is None:
odd = c
else:
odd = -1
break
if odd == -1:
print(-1)
exit()
target = [None]*len(S)
assigned = [False]*len(S)
if odd is not None:
l = list(indices[odd])
i = l[len(l)//2]
target[len(target)//2] = i
assigned[i] = True
l = deque(l[:len(l)//2] + l[len(l)//2+1:])
j = 0
for i in range(len(S)//2):
while assigned[j]:
j += 1
l = indices[S[j]]
a = l.popleft()
b = l.pop()
assert a == j
target[i] = a
target[len(S)-i-1] = b
assigned[a] = True
assigned[b] = True
print(count_inversions(target))
``` | output | 1 | 48,638 | 0 | 97,277 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,639 | 0 | 97,278 |
"Correct Solution:
```
"""
どれとペアになるかは最初から確定
位置を決めれば後は転倒数
"""
import sys
def bitadd(a,w,bit): #aにwを加える(1-origin)
x = a
while x <= (len(bit)-1):
bit[x] += w
x += x & (-1 * x)
def bitsum(a,bit): #ind 1～aまでの和を求める
ret = 0
x = a
while x > 0:
ret += bit[x]
x -= x & (-1 * x)
return ret
S = input()
dic = {}
for i,s in enumerate(S):
if s not in dic:
dic[s] = []
dic[s].append(i)
pair = [None] * len(S)
lis = [None] * len(S)
for i in dic:
for j in range(len(dic[i]) // 2):
pair[dic[i][j]] = dic[i][-1-j]
pair[dic[i][-1-j]] = -1
numnone = 0
for i in pair:
if i == None:
numnone += 1
if numnone > 1:
print (-1)
sys.exit()
nmax = 0
for i,num in enumerate(pair):
if num == None:
lis[i] = len(S)//2
if num != None and num >= 0:
lis[i] = nmax
lis[num] = len(S)-1-nmax
nmax += 1
BIT = [0] * (len(S)+1)
ans = 0
lis.reverse()
for i,num in enumerate(lis):
num += 1
ans += bitsum(num,BIT)
bitadd(num,1,BIT)
print (ans)
``` | output | 1 | 48,639 | 0 | 97,279 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,640 | 0 | 97,280 |
"Correct Solution:
```
#!/usr/bin/env python3
class Bit:
def __init__(self, n):
self.size = n
self.tree = [0] * n
def sum(self, i):
s = 0
i -= 1
while i >= 0:
s += self.tree[i]
i = (i & (i + 1)) - 1
return s
def add(self, i, x):
while i < self.size:
self.tree[i] += x
i |= i + 1
a = ord('a')
def make_index(s):
index = [[] for _ in range(26)]
for i, ch in enumerate(s):
index[ord(ch) - a].append(i)
return index
def solve(s):
n = len(s)
index = make_index(s)
odd = None
for code, char_pos in enumerate(index):
if len(char_pos) % 2 == 1:
if odd is not None:
return -1
odd = code
bit = Bit(n)
ans = 0
cnt = 0
for i in range(n):
if bit.sum(i + 1) - bit.sum(i) == 1:
continue
code = ord(s[i]) - a
if code == odd and index[code][-1] == i:
continue
cnt += 1
j = index[code].pop()
ans += n - cnt - (j - bit.sum(j))
bit.add(j, 1)
if n // 2 <= cnt:
break
if odd is not None:
j = index[odd][-1]
ans += abs(n // 2 - (j - bit.sum(j)))
return ans
def main():
s = input()
print(solve(s))
if __name__ == '__main__':
main()
``` | output | 1 | 48,640 | 0 | 97,281 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,641 | 0 | 97,282 |
"Correct Solution:
```
s = input()
cnt = [0] * 26
n = len(s)
for c in s:
cnt[ord(c) - ord('a')] += 1
odd = -1
for i in range(26):
if cnt[i] % 2 == 1:
if odd != -1:
print(-1)
exit()
odd = i
cnt2 = [[] for i in range(26)]
nums = []
left = 0
for i in range(len(s)):
c = s[i]
ind = ord(c) - ord('a')
if len(cnt2[ind]) * 2 + 1 == cnt[ind]:
cnt2[ind].append((n-1)//2)
nums.append((n-1)//2)
elif len(cnt2[ind]) <= (cnt[ind]-1)//2:
cnt2[ind].append(left)
nums.append(left)
left += 1
else:
num = n - 1 - cnt2[ind][cnt[ind]-1-len(cnt2[ind])]
cnt2[ind].append(num)
nums.append(num)
ans = 0
#print(nums)
bit = [0] * (n+1)
def add(x):
global bit
x += 1
while x <= n:
bit[x] += 1
x += x & -x
def sum(x):
x += 1
res = 0
while x:
res += bit[x]
x -= x & -x
return res
for num in nums[::-1]:
ans += sum(num)
add(num)
print(ans)
``` | output | 1 | 48,641 | 0 | 97,283 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,642 | 0 | 97,284 |
"Correct Solution:
```
"""
まず、奇数個存在する文字種が複数ある場合は、回文にできない。
それ以外の場合は、回文にできる。
次に、操作の最小回数は、回文になった場合の各文字のインデックスを求めておき、BITを使って、入れ替えが必要な回数を求めて置く
"""
from collections import Counter
S = input()
N = len(S)
#各文字の出現回数をカウント
apperance = Counter(S)
#回文を作成できるか判定
flag = False
for k,v in apperance.items():
if v%2==1:
if flag:
print(-1)
exit()
else:
flag = True
t = k
#place[s] -> 文字sの出現位置
place = {}
for i in range(N):
s = S[i]
if s not in place:
place[s] = []
place[s].append(i)
#memo[i] -> Sのi文字目の回文上でのインデックス
memo = [-1] *(N)
#回文前半、後半に含まれることになる文字に、回文上でのインデックスを割り当てる。
tmp = 0
tmpApperance = {}
for i in range(N):
s = S[i]
if s not in tmpApperance:
tmpApperance[s] = 1
else:
tmpApperance[s] += 1
if tmpApperance[s] <= apperance[s]//2:
memo[i] = tmp
backIdx = place[s][-tmpApperance[s]]
memo[backIdx] = N-tmp-1
tmp += 1
#回文の真ん中に含まれることになる文字に、回文上でのインデックスを割り当てる。
if flag:
idx = N//2
memo[place[t][len(place[t])//2]] = idx
class BIT:
def __init__(self,n):
self.size=n
self.tree = [0]*(n+1)
def sum(self,i):
s = 0
while i>0:
s += self.tree[i]
i -= i&-i
return s
def add(self,i,x):
while i<=self.size:
self.tree[i] += x
i += i&-i
bit = BIT(N)
cnt = 0
for i in range(N):
m = memo[i]+1
bit.add(m,1)
cnt += bit.sum(N)-bit.sum(m)
print(cnt)
``` | output | 1 | 48,642 | 0 | 97,285 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,643 | 0 | 97,286 |
"Correct Solution:
```
from string import ascii_lowercase
class Bit:
def __init__(self, n):
self.size = n
self.tree = [0] * (n + 1)
def sum(self, i):
s = 0
while i > 0:
s += self.tree[i]
i -= i & -i
return s
def add(self, i, x):
while i <= self.size:
self.tree[i] += x
i += i & -i
def solve(s):
indices = {c: [] for c in ascii_lowercase}
for i, c in enumerate(s):
indices[c].append(i)
n = len(s)
center = n // 2
bubbles = [-1] * n
odd_flag = False
pairs = []
for c, ids in indices.items():
cnt = len(ids)
if cnt & 1:
if odd_flag:
return -1
odd_flag = True
bubbles[ids[cnt // 2]] = center + 1
for i in range(cnt // 2):
li, ri = ids[i], ids[-i - 1]
pairs.append((li, ri))
pairs.sort()
for i, (li, ri) in enumerate(pairs):
bubbles[li] = i + 1
bubbles[ri] = n - i
ans = 0
bit = Bit(n)
for i, m in enumerate(bubbles):
ans += i - bit.sum(m)
bit.add(m, 1)
return ans
print(solve(input()))
``` | output | 1 | 48,643 | 0 | 97,287 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,644 | 0 | 97,288 |
"Correct Solution:
```
from collections import defaultdict, deque
from heapq import heappop, heappush
from string import ascii_lowercase as abc
class BIT:
def __init__(self, N):
# Nは入れたい要素の個数
self.size = 2 ** (int.bit_length(N+1))
self.tree = [0]*(self.size + 1)
def sum(self, i):
res = 0
while i:
res += self.tree[i]
i -= (i & -(i))
return res
def add(self, i, x):
if i == 0:
return
while i <= self.size:
self.tree[i] += x
i += (i & -(i))
D = [deque() for _ in range(26)]
S = input()
N = len(S)
for i in range(len(S)):
D[ord(S[i])-97].append(i)
M = [len(D[i])%2 for i in range(26)]
if sum(M) >= 2:
print(-1)
exit()
odd = sum(M)
Q = []
for c in range(26):
if len(D[c]) >= 2:
l = D[c].popleft()
r = D[c].pop()
a = l * 1
b = N - 1 - r
if b < a:
a, b = b, a
heappush(Q, (a, b, l, r, c))
T = [0]*(N//2)
for i in range(N//2):
_, _, l, r, c = heappop(Q)
T[i] = c
if len(D[c]) >= 2:
l = D[c].popleft()
r = D[c].pop()
a = l * 1
b = N - 1 - r
if b < a:
a, b = b, a
heappush(Q, (a, b, l, r, c))
L = [[] for i in range(26)]
for i in range(N//2):
L[T[i]].append(N-1-i)
if odd:
L[M.index(1)].append(N//2)
for i in range(N//2-1, -1, -1):
L[T[i]].append(i)
bit = BIT(N)
ans = 0
for i in range(N):
j = L[ord(S[i]) - 97].pop()
ans += i - bit.sum(j+1)
bit.add(j+1, 1)
print(ans)
``` | output | 1 | 48,644 | 0 | 97,289 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S consisting of lowercase English letters. Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.
Constraints
* 1 \leq |S| \leq 2 × 10^5
* S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
If we cannot turn S into a palindrome, print `-1`. Otherwise, print the minimum required number of operations.
Examples
Input
eel
Output
1
Input
ataatmma
Output
4
Input
snuke
Output
-1 | instruction | 0 | 48,645 | 0 | 97,290 |
"Correct Solution:
```
import sys
input = sys.stdin.readline
S = list(input().rstrip())
L = len(S)
# binary indexed tree
bit = [0 for _ in range(L+1)]
# 0からiまでの区間和
# 立っているビットを下から処理
def query_sum(i):
s = 0
while i > 0:
s += bit[i]
i -= i & -i
return s
# i番目の要素にxを足す
# 覆ってる区間すべてに足す
def add(i, x):
while i <= L:
bit[i] += x
i += i & -i
def main():
A = {}
for i, s in enumerate(S):
if not s in A.keys():
A[s] = [i]
else:
A[s].append(i)
odd = 0
dic = {}
for al, c in A.items():
dic[al] = 0
if len(c)%2 != 0:
odd += 1
if odd > 1:
print(-1)
else:
make_ind = []
for s, B in A.items():
l = len(B)
if l%2 == 1:
mid = B[l//2]
for j, b in enumerate(B):
if j < l//2:
make_ind.append(b)
make_ind.sort()
IND = [None]*L
for i, m in enumerate(make_ind):
s = S[m]
IND[m] = i+1
inv = A[s][len(A[s])-1-dic[s]]
IND[inv] = L-i
dic[s] += 1
if L%2 == 1:
IND[mid] = L//2+1
ans = 0
for j, a in enumerate(IND):
ans += j - query_sum(a)
add(a, 1)
print(ans)
if __name__ == "__main__":
main()
``` | output | 1 | 48,645 | 0 | 97,291 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,889 | 0 | 97,778 |
Tags: brute force, strings
Correct Solution:
```
import os
from math import fabs
alphabet_A = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
alphabet_C = 'CDEFGHIJKLMNOPQRSTUVWXYZAB'
alphabet_T = 'TUVWXYZABCDEFGHIJKLMNOPQRS'
alphabet_G = 'GHIJKLMNOPQRSTUVWXYZABCDEF'
target = 'ACTG'
A_count_map = {}
C_count_map = {}
T_count_map = {}
G_count_map = {}
for i in range(26):
A_count_map[alphabet_A[i]] = int(min(fabs(i), fabs(26 - i)))
C_count_map[alphabet_C[i]] = int(min(fabs(i), fabs(26 - i)))
T_count_map[alphabet_T[i]] = int(min(fabs(i), fabs(26 - i)))
G_count_map[alphabet_G[i]] = int(min(fabs(i), fabs(26 - i)))
def _f(n, s):
result = 10000000000
for i in range(len(s) - 3):
result = min(
result,
A_count_map[s[i]] + C_count_map[s[i + 1]] + T_count_map[s[i + 2]] + G_count_map[s[i + 3]]
)
return result
def f(n, s):
return _f(n, s)
if os.environ.get('DEBUG', False):
print(f"{f(4, 'ZCTH')} = 2")
print(f"{f(5, 'ZDATG')} = 5")
print(f"{f(6, 'AFBAKC')} = 16")
else:
n = int(input())
s = input()
print(f(n, s))
``` | output | 1 | 48,889 | 0 | 97,779 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,890 | 0 | 97,780 |
Tags: brute force, strings
Correct Solution:
```
n=int(input())
x=input()
c=0
y=[0]*(n-3)
for i in range (n-3):
c=0
d=ord(x[i])
c+=min(91-d,d-65)
d=ord(x[i+3])
c+=min(abs(71-d),97-d)
d=ord(x[i+2])
c+=min(abs(84-d),abs(58-d))
d=ord(x[i+1])
c+=min(abs(67-d),93-d)
y[i]=c
print(min(y))
``` | output | 1 | 48,890 | 0 | 97,781 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,891 | 0 | 97,782 |
Tags: brute force, strings
Correct Solution:
```
n = int(input())
s = input()
glob = float('inf')
for i in range(len(s)-3):
sub = s[i:i+4]
curr = 0
A = ord('A') - 65
C = ord('C') - 65
T = ord('T') - 65
G = ord('G') - 65
s1 = ord(sub[0]) - 65
s2 = ord(sub[1]) - 65
s3 = ord(sub[2]) - 65
s4 = ord(sub[3]) - 65
g = [s1,s2,s3,s4]
t = [A,C,T,G]
for i,j in zip(g,t):
f = i-j
b = j-i
if f < 0:
curr += min(26 + f, b)
elif b < 0:
curr += min(f, 26 + b)
glob = min(glob, curr)
print(glob)
``` | output | 1 | 48,891 | 0 | 97,783 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,892 | 0 | 97,784 |
Tags: brute force, strings
Correct Solution:
```
def f(l):
# print(l)
a=min(abs(l[0]-ord("A")),90-l[0]+1)
c=min(abs(l[1]-ord("C")),90-l[1]+3)
t=min(abs(l[2]-ord("T")),90-l[2]+20)
g=min(abs(l[3]-ord("G")),90-l[3]+7)
a=min(a,90-ord("A")+l[0]-64)
c=min(c,90-ord("C")+l[1]-64)
t=min(t,90-ord("T")+l[2]-64)
g=min(g,90-ord("G")+l[3]-64)
# print(a,c,t,g)
return a+c+t+g
n=int(input())
s=list(map(lambda x:ord(x),list(input())))
lx=[]
for i in range(n-3):
lx.append(f(s[i:i+4]))
print(min(lx))
``` | output | 1 | 48,892 | 0 | 97,785 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,893 | 0 | 97,786 |
Tags: brute force, strings
Correct Solution:
```
if __name__ == "__main__":
N = int(input())
S = [ord(c) for c in input()]
target = [ord(c) for c in "ACTG"]
res = 1234567890
for i in range(N - 4 + 1):
tmp = 0
for j in range(4):
tmp += min((target[j] - S[i + j]) % 26, (S[i + j] - target[j]) % 26)
res = min(tmp, res)
print(res)
``` | output | 1 | 48,893 | 0 | 97,787 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,894 | 0 | 97,788 |
Tags: brute force, strings
Correct Solution:
```
# -*- coding: utf-8 -*-
import sys
import copy
sys.setrecursionlimit(1000000)
# input = sys.stdin.readline
# ~~~~~~~~~~~~~~~~~~~~~_(＾～＾ ｣ ∠)_~~~~~~~~~~~~~~~~~~~~~
N = int(input())
S = input().rstrip()
ACTG = "ACTG"
actg = [[None] * N for _ in range(4)]
for i in range(4):
to = ord(ACTG[i]) - ord("A")
for j in range(N):
c = ord(S[j]) - ord("A")
cnt1, cnt2 = 0, 0
while c != to:
c += 1
cnt1 += 1
c %= 26
c = ord(S[j]) - ord("A")
while c != to:
c -= 1
c += 26
c %= 26
cnt2 += 1
actg[i][j] = min(cnt1, cnt2)
ans = 1e10
for i in range(N - 3):
sum = 0
for j in range(4):
sum += actg[j][i + j]
ans = min(ans, sum)
print(ans)
``` | output | 1 | 48,894 | 0 | 97,789 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,895 | 0 | 97,790 |
Tags: brute force, strings
Correct Solution:
```
n=int(input())
s=input()
t=[]
for k in range(n-4+1):
a=min( abs(ord(s[k])-ord('A')) ,abs((ord(s[k])-96)+122-ord('A')),abs((ord('A')-96)+122-ord(s[k])))
b=min( abs( ord(s[k+1])-ord('C')) ,abs((ord(s[k+1])-96)+122-ord('C')),abs((ord('C')-96)+122-ord(s[k+1])))
c=min( abs( ord(s[k+2])-ord('T')) ,abs((ord(s[k+2])-96)+122-ord('T')),abs((ord('T')-96)+122-ord(s[k+2])))
d=min( abs( ord(s[k+3])-ord('G') ),abs((ord(s[k+3])-96)+122-ord('G')),abs((ord('G')-96)+122-ord(s[k+3])))
t.append(a+b+c+d)
print(min(t))
``` | output | 1 | 48,895 | 0 | 97,791 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Today in the scientific lyceum of the Kingdom of Kremland, there was a biology lesson. The topic of the lesson was the genomes. Let's call the genome the string "ACTG".
Maxim was very boring to sit in class, so the teacher came up with a task for him: on a given string s consisting of uppercase letters and length of at least 4, you need to find the minimum number of operations that you need to apply, so that the genome appears in it as a substring. For one operation, you can replace any letter in the string s with the next or previous in the alphabet. For example, for the letter "D" the previous one will be "C", and the next — "E". In this problem, we assume that for the letter "A", the previous one will be the letter "Z", and the next one will be "B", and for the letter "Z", the previous one is the letter "Y", and the next one is the letter "A".
Help Maxim solve the problem that the teacher gave him.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Input
The first line contains a single integer n (4 ≤ n ≤ 50) — the length of the string s.
The second line contains the string s, consisting of exactly n uppercase letters of the Latin alphabet.
Output
Output the minimum number of operations that need to be applied to the string s so that the genome appears as a substring in it.
Examples
Input
4
ZCTH
Output
2
Input
5
ZDATG
Output
5
Input
6
AFBAKC
Output
16
Note
In the first example, you should replace the letter "Z" with "A" for one operation, the letter "H" — with the letter "G" for one operation. You will get the string "ACTG", in which the genome is present as a substring.
In the second example, we replace the letter "A" with "C" for two operations, the letter "D" — with the letter "A" for three operations. You will get the string "ZACTG", in which there is a genome. | instruction | 0 | 48,896 | 0 | 97,792 |
Tags: brute force, strings
Correct Solution:
```
def result(s):
tmp = 0
s1 = 'ACTG'
for i in range(4):
a, b = ord(s[i]), ord(s1[i])
a, b = max(a, b), min(a, b)
tmp += min(a-b, b-ord('A')+ord('Z')-a+1)
return tmp
n = int(input())
s = input()
res = result(s[0:4])
for i in range(1,n-3):
res = min(res, result(s[i:i+4]))
print(res)
``` | output | 1 | 48,896 | 0 | 97,793 |
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