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109k
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float64 0
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int64 194
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|
|---|---|---|---|---|---|
Provide tags and a correct Python 3 solution for this coding contest problem.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
|
instruction
| 0
| 97,137
| 0
| 194,274
|
Tags: brute force, constructive algorithms, greedy, math, strings
Correct Solution:
```
n = int(input())
if n == 1:
print("codeforces")
exit()
num = 1
while num ** 10 < n:
num += 1
s = list("codeforces")
temp = 10
for i in reversed(range(11)):
if ((num ** i) * ((num - 1) ** (10 - i))) < n:
temp = i + 1
break
ans = ""
for i in range(10):
ans += s[i] * num
if i + 1 == temp:
num -= 1
print(ans)
```
|
output
| 1
| 97,137
| 0
| 194,275
|
Provide tags and a correct Python 3 solution for this coding contest problem.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
|
instruction
| 0
| 97,138
| 0
| 194,276
|
Tags: brute force, constructive algorithms, greedy, math, strings
Correct Solution:
```
def tc():
k = int(input())
base = 1
while pow(base, 10) < k:
base += 1
less = 0
while pow(base, 10 - less) * pow(base - 1, less) > k:
less += 1
if pow(base, 10 - less) * pow(base - 1, less) < k:
less -= 1
ans = ''
s = 'codeforces'
for ch in s[:less]:
ans += ch * (base - 1)
for ch in s[less:]:
ans += ch * base
print(ans)
################################
# T = int(input())
# for _ in range(T):
# tc()
tc()
```
|
output
| 1
| 97,138
| 0
| 194,277
|
Provide tags and a correct Python 3 solution for this coding contest problem.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
|
instruction
| 0
| 97,139
| 0
| 194,278
|
Tags: brute force, constructive algorithms, greedy, math, strings
Correct Solution:
```
def prod(arr):
ans=1
for i in arr:
ans *= i
return ans
def find_opt(arr,n):
if(prod(arr)>=n):
return arr
m = min(arr)
min_idx = arr.index(m)
arr[min_idx]+=1
return find_opt(arr,n)
n = int(input())
arr = find_opt([1]*10,n)
ans = ""
brr =['c','o','d','e','f','o','r','c','e','s']
for i in range(10):
ans += brr[i]*arr[i]
print(ans)
```
|
output
| 1
| 97,139
| 0
| 194,279
|
Provide tags and a correct Python 3 solution for this coding contest problem.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
|
instruction
| 0
| 97,140
| 0
| 194,280
|
Tags: brute force, constructive algorithms, greedy, math, strings
Correct Solution:
```
a=int(input())
l=[0,0,0,0,0,0,0,0,0,0]
id=0
g=1
while(1):
g=1
if id==10:
id=0
g=1
for j in range(10):
g=g*l[j]
if g>=a:
break
l[id]=l[id]+1
id=id+1
for i in range(l[0]):
print('c',end='')
for i in range(l[1]):
print('o',end='')
for i in range(l[2]):
print('d',end='')
for i in range(l[3]):
print('e',end='')
for i in range(l[4]):
print('f',end='')
for i in range(l[5]):
print('o',end='')
for i in range(l[6]):
print('r',end='')
for i in range(l[7]):
print('c',end='')
for i in range(l[8]):
print('e',end='')
for i in range(l[9]):
print('s',end='')
```
|
output
| 1
| 97,140
| 0
| 194,281
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
n=int(input())
l=[1]*10
p=1
j=0
while(p<n):
k=l[j]
l[j]+=1
p=(p//k)*l[j]
j=(j+1)%10
ss='codeforces'
m = [ ss[i]*l[i] for i in range(10)]
print(''.join(m))
```
|
instruction
| 0
| 97,141
| 0
| 194,282
|
Yes
|
output
| 1
| 97,141
| 0
| 194,283
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
k = int(input())
def product(s):
res = 1
for e in s:
res *= e
return res
string = "codeforces"
nums = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
index = 0
while True:
p = product(nums)
if p < k:
nums[index] += 1
index = (index + 1) % len(nums)
else:
break
result = ""
for i, e in enumerate(nums):
result += e * string[i]
print(result)
```
|
instruction
| 0
| 97,142
| 0
| 194,284
|
Yes
|
output
| 1
| 97,142
| 0
| 194,285
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
k = int(input())
def getperm(occ):
val = 1
for v in occ:
val *= v
return val
letters = ['c', 'o', 'd', 'e', 'f', 'o', 'r', 'c', 'e', 's']
occurences = [1 for x in range(len(letters))]
permutations = 1
location = 0
while getperm(occurences) < k:
occurences[location] += 1
location += 1
location %= len(occurences)
for i, v in enumerate(occurences):
print(letters[i]*v, end='')
print()
```
|
instruction
| 0
| 97,143
| 0
| 194,286
|
Yes
|
output
| 1
| 97,143
| 0
| 194,287
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
# -*- coding: utf-8 -*-
"""
Created on Wed Jun 24 09:24:46 2020
@author: Dark Soul
"""
def mult(x):
res=1
for i in range(len(x)):
x[i]=int(x[i])
res=res*x[i]
return res
import math
n=input('')
n=int(n)
k=0
sign=0
cnt=[1,1,1,1,1,1,1,1,1,1]
str=['c','o','d','e','f','o','r','c','e','s']
str_final=''
i=0
j=0
while mult(cnt)<=n:
if mult(cnt)==n:
break;
cnt[i]=cnt[i]+1
i=i+1
if i>9:
i=0
for i in range(10):
str_final=str_final+str[i]*cnt[i]
print(str_final)
```
|
instruction
| 0
| 97,144
| 0
| 194,288
|
Yes
|
output
| 1
| 97,144
| 0
| 194,289
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
import math
k = int(input())
new = int(math.ceil(math.log2(k)) / 10)
# print(new)
new2 = math.ceil(math.log2(k)) % 10
# print(new2)
orig = list('codeforces')
ans = ''
if new > 0:
for i in range(10):
ans += orig[i] * ((1 + new + (i < new2)) * new)
else:
for i in range(10):
ans += orig[i] * (1 + new + (i < new2))
print(ans)
```
|
instruction
| 0
| 97,145
| 0
| 194,290
|
No
|
output
| 1
| 97,145
| 0
| 194,291
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
from math import inf as inf
from math import *
from collections import *
import sys
from itertools import permutations
input=sys.stdin.readline
t=1
while(t):
t-=1
n=int(input())
if(n==1):
print("codeforces")
continue
l=[[1,'c'],[1,'o'],[1,'d'],[1,'e'],[1,'f'],[1,'o'],[1,'r'],[1,'c'],[1,'e'],[1,'s']]
p=1
c1=0
while(p<n):
p=p*2
c1+=1
for i in range(c1):
l[i%10][0]*=2
for i in l:
print(i[1]*i[0],end="")
print()
```
|
instruction
| 0
| 97,146
| 0
| 194,292
|
No
|
output
| 1
| 97,146
| 0
| 194,293
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
import math
def solve():
t = int(input())
current = 0
letters = ['c', 'o', 'd', 'e', 'f', 'o', 'r', 'c', 'e', 's']
arr = [1] * len(letters)
product = 1
power = 2
while product < t:
arr[current] += 1
product *= power
current += 1
if current == len(letters):
current = 0
for i in range(len(letters)):
print(letters[i] * arr[i], end="")
print()
solve()
```
|
instruction
| 0
| 97,147
| 0
| 194,294
|
No
|
output
| 1
| 97,147
| 0
| 194,295
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Karl likes Codeforces and subsequences. He wants to find a string of lowercase English letters that contains at least k subsequences codeforces. Out of all possible strings, Karl wants to find a shortest one.
Formally, a codeforces subsequence of a string s is a subset of ten characters of s that read codeforces from left to right. For example, codeforces contains codeforces a single time, while codeforcesisawesome contains codeforces four times: codeforcesisawesome, codeforcesisawesome, codeforcesisawesome, codeforcesisawesome.
Help Karl find any shortest string that contains at least k codeforces subsequences.
Input
The only line contains a single integer k (1 ≤ k ≤ 10^{16}).
Output
Print a shortest string of lowercase English letters that contains at least k codeforces subsequences. If there are several such strings, print any of them.
Examples
Input
1
Output
codeforces
Input
3
Output
codeforcesss
Submitted Solution:
```
k = int(input())
primes = []
a = 2
while k >= a*a:
while k % a == 0:
primes.append(a)
k //= a
a += 1
if k != 1:
primes.append(k)
primes = list(reversed(sorted(primes)))
K = [1] * 10
for p in primes:
idx = K.index(min(K))
K[idx] *= p
s = [c*K[i] for i, c in enumerate('codeforces')]
print(''.join(s))
```
|
instruction
| 0
| 97,148
| 0
| 194,296
|
No
|
output
| 1
| 97,148
| 0
| 194,297
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,183
| 0
| 194,366
|
Tags: data structures, greedy, strings
Correct Solution:
```
def mergesort(l,n):
if n==1:
return l,0
else:
a,ans1=mergesort(l[0:n//2],n//2)
b,ans2=mergesort(l[n//2:],n-n//2)
c,ans3=combine(a,n//2,b,n-n//2)
#print (c,ans1,ans2,ans3)
return (c,ans1+ans2+ans3)
def combine(l1,n,l2,m):
i=0
j=0
ans=[]
inversions=0
while (i<n and j<m):
if l1[i]<=l2[j]:
ans.append(l1[i])
i+=1
else:
ans.append(l2[j])
inversions += n-i
j+=1
if i==n:
for k in range(j,m):
ans.append(l2[k])
elif j==m:
for k in range(i,n):
ans.append(l1[k])
return (ans,inversions)
n = int(input())
start = input()
s = start[::-1]
loc = {}
for i in range(n):
if s[i] in loc:
loc[s[i]].append(i)
else:
loc[s[i]] = [i]
new = {}
for i in loc:
new[i] = loc[i][::-1]
arr = []
for i in range(n):
arr.append(new[start[i]].pop())
# print (arr)
print (mergesort(arr, len(arr))[1])
```
|
output
| 1
| 97,183
| 0
| 194,367
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,184
| 0
| 194,368
|
Tags: data structures, greedy, strings
Correct Solution:
```
import functools
import datetime
import math
import collections
import heapq
maxn = int(2e5 + 5)
n = int(input())
s = input()
t = s[::-1]
a = [[] for i in range(31)]
# for i in range(30):
# a.append([])
tree = [0] * maxn
num = [0] * maxn
g = [0] * 30
def lowbit(x):
return x & (-x)
def tadd(x, val):
while x <= maxn:
tree[x] += val
x += lowbit(x)
def tsum(x):
ans = 0
while x > 0:
ans += tree[x]
x -= lowbit(x)
return ans
for i in range(0, len(t)):
ch = ord(t[i]) - ord('a')
a[ch].append(i)
for i in range(0, len(s)):
ch = ord(s[i]) - ord('a')
num[i] = a[ch][g[ch]]
g[ch] += 1
ans = 0
for i in range(0, len(s)):
tadd(num[i] + 1, 1)
# print(i+1-tsum(num[i]+1))
ans += i + 1 - tsum(num[i] + 1)
print(ans)
```
|
output
| 1
| 97,184
| 0
| 194,369
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,185
| 0
| 194,370
|
Tags: data structures, greedy, strings
Correct Solution:
```
N = int(input())
S = input()
dic = {}
for i, s in enumerate(S):
if s in dic:
dic[s].append(i)
else:
dic[s] = [i]
X = list(range(N-1, -1, -1))
for c, idcs in dic.items():
for p, q in zip(idcs, reversed(idcs)):
X[p] = N-1-q
class BIT():
def __init__(self, N):
self.N = N
self.T = [0]*(N+1)
def add(self, i, x):
i += 1
while i <= self.N:
self.T[i] += x
i += i & -i
def _sum(self, i): #[0,i)
ret = 0
while i > 0:
ret += self.T[i]
i ^= i & -i
return ret
def sum(self, l, r): #[l,r)
return self._sum(r)-self._sum(l)
def lower_bound(self, w):
if w <= 0:
return 0
x = 0
k = 1<<self.N.bit_length()
while k:
if x+k <= self.N and self.T[x+k] < w:
w -= self.t[x+k]
x += k
k >>= 1
return x+1
b = BIT(N)
ans = 0
for i, x in enumerate(X):
ans += i - b._sum(x+1)
b.add(x, 1)
print(ans)
```
|
output
| 1
| 97,185
| 0
| 194,371
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,186
| 0
| 194,372
|
Tags: data structures, greedy, strings
Correct Solution:
```
# cook your dish here
import heapq
import collections
from math import log2
import itertools
from functools import lru_cache
from sys import setrecursionlimit as srl
srl(2*10**6)
N = 200001
class fenwick:
def __init__(self,n):
self.n = n
self.arr = [0]*(n+1)
def update(self,ind,x):
if ind <= 0:
return
while ind <= self.n:
self.arr[ind] += x
ind += (ind)&(-ind)
def query(self,ind):
s = 0
while ind > 0:
s += self.arr[ind]
ind -= (ind)&(-ind)
return s
def solve(n,s):
fen = fenwick(n+1)
inv = 0
t = s[::-1]
chars = collections.defaultdict(collections.deque)
for i in range(n):
chars[ord(s[i])-ord('a')].append(i)
for i in range(n):
v = chars[ord(t[i])-ord('a')].popleft()
fen.update(v+1,1)
v += (i+1)-fen.query(v+1)
inv += v-i
return inv
n = int(input())
s = input()
print(solve(n,s))
```
|
output
| 1
| 97,186
| 0
| 194,373
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,187
| 0
| 194,374
|
Tags: data structures, greedy, strings
Correct Solution:
```
def mergeSortswap(arr):
if len(arr) >1:
mid = len(arr)//2
L = arr[:mid]
R = arr[mid:] # into 2 halves
x = mergeSortswap(L) # Sorting the first half
y = mergeSortswap(R)
i = j = k = 0
z = 0
while i < len(L) and j < len(R):
if L[i] < R[j]:
arr[k] = L[i]
i+= 1
else:
arr[k] = R[j]
z += (mid-i)
j+= 1
k+= 1
while i < len(L):
arr[k] = L[i]
i+= 1
k+= 1
while j < len(R):
arr[k] = R[j]
j+= 1
k+= 1
return z+x+y
else:
return 0
import collections,bisect
n = int(input())
s = input().strip(' ')
d = collections.defaultdict(collections.deque)
s_reverse = s[::-1]
if s == s_reverse:
print(0)
else:
for i in range(n):
d[s_reverse[i]].append(i)
to_sort = []
for i in range(n):
ind = d[s[i]].popleft()
to_sort.append(ind)
c = mergeSortswap(to_sort)
print(c)
```
|
output
| 1
| 97,187
| 0
| 194,375
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,188
| 0
| 194,376
|
Tags: data structures, greedy, strings
Correct Solution:
```
n = int(input())
s = input()
SZ = 30
lim = n + 233
g = [[] for i in range(SZ)]
a = [0] * SZ
for i in range(n):
cur = ord(s[i]) - 97
g[cur].append(i)
bit = [0] * (lim+1)
def lowbit(x):
return x & (-x)
def add(pos, val):
while pos <= lim:
bit[pos] += val
pos += lowbit(pos)
def query(pos):
res = 0
while pos:
res += bit[pos]
pos -= lowbit(pos)
return res
ans = 0
for i in range(n-1, -1, -1):
cur = ord(s[i]) - 97
val = g[cur][a[cur]]
ans += val - query(val+1)
a[cur] += 1
add(val+1, 1)
print(ans)
```
|
output
| 1
| 97,188
| 0
| 194,377
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,189
| 0
| 194,378
|
Tags: data structures, greedy, strings
Correct Solution:
```
import sys
input=sys.stdin.readline
def segment_tree(ar,n):
data=[0]*n+ar.copy()
for i in range(n-1,0,-1):
data[i]+=(data[i*2]+data[i*2+1])
return data
def update(data,idx,n,value):
idx+=n
data[idx]+=value
while(idx>1):
idx//=2
data[idx]+=value
def summation(data,l,r,n):
l+=n
r+=n
maxi=0
while(l<r):
if(l%2!=0):
maxi+=data[l]
l+=1
if(r%2!=0):
r-=1
maxi+=data[r]
l//=2
r//=2
return maxi
n=int(input())
st=list(input())[:-1]
ar=[]
dic={}
for i in range(n):
ar.append(1)
if(st[i] in dic):
dic[st[i]].append(i)
else:
dic[st[i]]=[i]
ar[0]=0
for i in dic:
dic[i]=dic[i][::-1]
rev=st[::-1]
data=segment_tree(ar, n)
ans=0
for i in range(n):
cur=rev[i]
ind=dic[cur].pop()
ind1=summation(data, 0, ind+1, n)
tem=ind1-i
ans+=tem
if(tem):
update(data, 0, n, 1)
update(data,ind,n,-ar[ind])
print(ans)
```
|
output
| 1
| 97,189
| 0
| 194,379
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
|
instruction
| 0
| 97,190
| 0
| 194,380
|
Tags: data structures, greedy, strings
Correct Solution:
```
from collections import defaultdict, Counter
class FenwickTree:
def __init__(self, n):
self.tree = [0] * (n + 1)
def _get(self, x):
res = 0
while x >= 1:
res += self.tree[x]
x -= x & -x
return res
def get(self, l, r):
return self._get(r) - self._get(l - 1)
def add(self, x, d):
while x < len(self.tree):
self.tree[x] += d
x += x & -x
def inversions(a):
n = len(a)
res = 0
count = FenwickTree(n)
for e in a:
res += count.get(e + 1, n)
count.add(e, 1)
return res
n = int(input())
s = input()
d = defaultdict(list)
for i, e in enumerate(s[::-1]):
d[e].append(i + 1)
c = Counter()
a = []
for e in s:
a.append(d[e][c[e]])
c[e] += 1
print(inversions(a))
```
|
output
| 1
| 97,190
| 0
| 194,381
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
from collections import defaultdict, deque
from heapq import heappush, heappop
from math import inf
ri = lambda : map(int, input().split())
ro = lambda : int(input())
class FW:
def __init__(self, N):
self.A = [0] * (N + 1)
def add(self, idx, val):
while idx < len(self.A):
self.A[idx] += val
idx += idx & -idx
def qry(self, idx):
sm = 0
while idx > 0:
sm += self.A[idx]
idx -= idx & -idx
return sm
def solve():
n = ro()
fw = FW(n)
s = input()
rev = s[::-1]
cnt = defaultdict(int)
indexes = defaultdict(list)
for i in range(n):
indexes[rev[i]].append(i)
inv = []
for i in range(n):
inv.append(indexes[s[i]][cnt[s[i]]])
cnt[s[i]] += 1
ans = 0
for i in range(n-1, -1, -1):
ans += fw.qry(inv[i]+1)
fw.add(inv[i]+1, 1)
print(ans)
t = 1
#t = int(input())
while t:
t -= 1
solve()
```
|
instruction
| 0
| 97,191
| 0
| 194,382
|
Yes
|
output
| 1
| 97,191
| 0
| 194,383
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
# aadiupadhyay
from heapq import heappop
import os.path
from math import gcd, floor, ceil
from collections import *
import sys
from heapq import *
mod = 1000000007
INF = float('inf')
def st(): return list(sys.stdin.readline().strip())
def li(): return list(map(int, sys.stdin.readline().split()))
def mp(): return map(int, sys.stdin.readline().split())
def inp(): return int(sys.stdin.readline())
def pr(n): return sys.stdout.write(str(n)+"\n")
def prl(n): return sys.stdout.write(str(n)+" ")
if os.path.exists('input.txt'):
sys.stdin = open('input.txt', 'r')
sys.stdout = open('output.txt', 'w')
def solve():
def update(ind, val):
while ind <= n:
BIT[ind] += val
ind += ind & -ind
def query(ind):
su = 0
while ind > 0:
su += BIT[ind]
ind -= ind & -ind
return su
n = inp()
s = ['&']+st()
d = defaultdict(list)
n += 1
for i in range(1, n):
d[s[i]].append(i)
BIT = [0]*(n+2)
ans = 0
p = [0]*(n+1)
for i in range(n-1, 0, -1):
last = d[s[n-i]].pop()
p[i] = last
for i in range(1, n):
c = query(n) - query(p[i])
ans += c
update(p[i], 1)
pr(ans)
for _ in range(1):
solve()
```
|
instruction
| 0
| 97,192
| 0
| 194,384
|
Yes
|
output
| 1
| 97,192
| 0
| 194,385
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
import os
import sys
from io import BytesIO, IOBase
_str = str
BUFSIZE = 8192
def str(x=b''):
return x if type(x) is bytes else _str(x).encode()
class FastIO(IOBase):
newlines = 0
def __init__(self, file):
self._fd = file.fileno()
self.buffer = BytesIO()
self.writable = 'x' in file.mode or 'r' not in file.mode
self.write = self.buffer.write if self.writable else None
def read(self):
while True:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
if not b:
break
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines = 0
return self.buffer.read()
def readline(self):
while self.newlines == 0:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
self.newlines = b.count(b'\n') + (not b)
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines -= 1
return self.buffer.readline()
def flush(self):
if self.writable:
os.write(self._fd, self.buffer.getvalue())
self.buffer.truncate(0), self.buffer.seek(0)
class IOWrapper(IOBase):
def __init__(self, file):
self.buffer = FastIO(file)
self.flush = self.buffer.flush
self.writable = self.buffer.writable
self.write = lambda s: self.buffer.write(s.encode('ascii'))
self.read = lambda: self.buffer.read().decode('ascii')
self.readline = lambda: self.buffer.readline().decode('ascii')
def inp():
return sys.stdin.readline().rstrip()
def mpint():
return map(int, inp().split(' '))
def itg():
return int(inp())
# ############################## import
# from ACgenerator.Y_Testing import get_code
from collections import defaultdict
def discretization(iterable):
""" [1, 2, 4, 2, 5] -> [0, 1, 2, 1, 3] """
iterable = tuple(iterable)
restore = sorted(set(iterable))
return list(map(dict(zip(restore, range(len(restore)))).__getitem__, iterable)), restore
class Fenwick:
""" Simpler FenwickTree """
def __init__(self, x):
self.bit = [0] * x
def update(self, idx, x):
"""updates bit[idx] += x"""
while idx < len(self.bit):
self.bit[idx] += x
idx |= idx + 1
def query(self, end):
"""calc sum(bit[:end])"""
x = 0
while end:
x += self.bit[end - 1]
end &= end - 1
return x
def findkth(self, k):
"""
Find largest idx such that sum(bit[:idx]) < k
(!) different from pyrival (just removed the '=')
"""
idx = -1
for d in reversed(range(len(self.bit).bit_length())):
right_idx = idx + (1 << d)
if right_idx < len(self.bit) and k > self.bit[right_idx]:
idx = right_idx
k -= self.bit[idx]
return idx + 1
def inversion(iterable):
"""
the number of j s.t (a[i] > a[j]) and (i < j) for each i
Example:
inversion([2, 3, 4, 2, 1])
[1, 2, 2, 1, 0]
"""
iterable = discretization(iterable)[0]
index = len(iterable)
bit = Fenwick(index)
result = [0] * index
for item in reversed(iterable):
index -= 1
result[index] = bit.query(item)
bit.update(item, 1)
return result
def discrete_by_permutation(seq1, seq2):
""" 'teenager', 'generate' -> 61325074 """
seq1, seq2 = reversed(seq1), tuple(seq2)
d_stack = defaultdict(lambda: [])
for index, item in enumerate(seq2):
d_stack[item].append(index)
return list(reversed([d_stack[item].pop() for item in seq1]))
def bubble_step(s1, s2):
"""
:return the minimum step that have to perform
s1 to s2 with swapping the neighboring elements
"""
return sum(inversion(discrete_by_permutation(s1, s2)))
# ############################## main
def main():
# print("YES" if solve() else "NO")
# print("yes" if solve() else "no")
# solve()
print(solve())
# for _ in range(itg()):
# print(solve())
def solve():
_, s = itg(), inp()
return bubble_step(s, s[::-1])
DEBUG = 0
URL = 'https://codeforces.com/contest/1430/problem/E'
if __name__ == '__main__':
if DEBUG:
import requests # ImportError: cannot import name 'md5' from 'sys' (unknown location)
from ACgenerator.Y_Test_Case_Runner import TestCaseRunner
runner = TestCaseRunner(main, URL)
inp = runner.input_stream
print = runner.output_stream
runner.checking()
else:
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
main()
# Please check!
```
|
instruction
| 0
| 97,193
| 0
| 194,386
|
Yes
|
output
| 1
| 97,193
| 0
| 194,387
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
#import modules here
import math,sys,os
#from itertools import permutations, combinations
from collections import defaultdict,deque,OrderedDict,Counter
import bisect as bi
#import heapq
from io import BytesIO, IOBase
mod=10**9+7
# region fastio
BUFSIZE = 8192
class FastIO(IOBase):
newlines = 0
def __init__(self, file):
self._fd = file.fileno()
self.buffer = BytesIO()
self.writable = "x" in file.mode or "r" not in file.mode
self.write = self.buffer.write if self.writable else None
def read(self):
while True:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
if not b:
break
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines = 0
return self.buffer.read()
def readline(self):
while self.newlines == 0:
b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
self.newlines = b.count(b"\n") + (not b)
ptr = self.buffer.tell()
self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
self.newlines -= 1
return self.buffer.readline()
def flush(self):
if self.writable:
os.write(self._fd, self.buffer.getvalue())
self.buffer.truncate(0), self.buffer.seek(0)
class IOWrapper(IOBase):
def __init__(self, file):
self.buffer = FastIO(file)
self.flush = self.buffer.flush
self.writable = self.buffer.writable
self.write = lambda s: self.buffer.write(s.encode("ascii"))
self.read = lambda: self.buffer.read().decode("ascii")
self.readline = lambda: self.buffer.readline().decode("ascii")
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")
#input functions
def minp(): return map(int, sys.stdin.readline().rstrip().split())
def linp(): return list(map(int, sys.stdin.readline().rstrip().split()))
def inp(): return int(input())
def print_list(l):
print(' '.join(map(str,l)))
#functions
def BinarySearch(a,x):
i=bi.bisect_left(a, x)
if i != len(a) and a[i] == x:
return i
else:
return -1
def gcd(a,b):
return math.gcd(a,b)
def is_prime(n):
"""returns True if n is prime else False"""
if n < 5 or n & 1 == 0 or n % 3 == 0:
return 2 <= n <= 3
s = ((n - 1) & (1 - n)).bit_length() - 1
d = n >> s
for a in [2, 325, 9375, 28178, 450775, 9780504, 1795265022]:
p = pow(a, d, n)
if p == 1 or p == n - 1 or a % n == 0:
continue
for _ in range(s):
p = (p * p) % n
if p == n - 1:
break
else:
return False
return True
def mulinverse(a):
return pow(a,mod-2,mod)
####################Let's Go Baby########################
from collections import defaultdict as dc
def reversePairs(nums):
if not nums:
return 0
res = 0
def merge(a,b):
nonlocal res
temp = []
i,j = 0,0
m = len(a)
n = len(b)
while i<m and j<n:
if a[i]<=b[j]:
temp.append(a[i])
i+=1
else:
temp.append(b[j])
j+=1
res+=m-i
if i<m:
temp+=a[i:]
else:
temp+=b[j:]
return temp
def mergesort(L):
length = len(L)
if length==1:
return L
k = length>>1
a = mergesort(L[:k])
b = mergesort(L[k:])
return merge(a,b)
mergesort(nums)
return res
n = inp()
s = input()
t = s[::-1]
res = 0
flag = [0]*(n)
dic = dc(int)
for i in range(n):
c = t[i]
key = s.find(c,dic[c])
dic[c] = key+1
flag[key] = i
#print(dic)
print(reversePairs(flag))
```
|
instruction
| 0
| 97,194
| 0
| 194,388
|
Yes
|
output
| 1
| 97,194
| 0
| 194,389
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
n=int(input())
s=input()
if s==s[::-1]:
print(0)
else:
print(n//2)
```
|
instruction
| 0
| 97,195
| 0
| 194,390
|
No
|
output
| 1
| 97,195
| 0
| 194,391
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
import sys
input=sys.stdin.readline
def update(inp,add,ar):
global n
while(inp<n):
ar[inp]+=add
inp+=(inp&(-inp))
def fun1(inp,ar):
global n
ans=0
while(inp):
ans+=ar[inp]
inp-=(inp&(-inp))
return ans
n=int(input())
st=list(input())
st=st[:-1]
li=[0]*(n+1)
rev=st[::-1]
dic={}
for i in range(n):
if(st[i] in dic):
dic[st[i]].append(i)
else:
dic[st[i]]=[i]
for i in dic:
dic[i]=dic[i][::-1]
ans=0
pas=0
j=0
for i in range(n):
while(st[j]=='-'):
j+=1
pas+=1
if(st[j]==rev[i]):
dic[st[j]].pop()
j+=1
else:
ind=dic[rev[i]][-1]+1
st[ind-1]='-'
dic[rev[i]].pop()
su=fun1(ind,li)
ans+=(ind-su-j-1+pas)
update(ind,1,li)
print(ans)
```
|
instruction
| 0
| 97,196
| 0
| 194,392
|
No
|
output
| 1
| 97,196
| 0
| 194,393
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
def update(inp,add,ar):
global n
while(inp<n):
ar[inp]+=add
inp+=(inp&(-inp))
def fun1(inp,ar):
global n
ans=0
while(inp):
ans+=ar[inp]
inp-=(inp&(-inp))
return ans
n=int(input())
st=list(input())
li=[0]*(n+1)
rev=st[::-1]
dic={}
for i in range(n):
if(st[i] in dic):
dic[st[i]].append(i)
else:
dic[st[i]]=[i]
for i in dic:
dic[i]=dic[i][::-1]
ans=0
pas=0
j=0
for i in range(n):
while(st[j]=='-'):
j+=1
pas+=1
if(st[j]==rev[i]):
dic[st[j]].pop()
j+=1
else:
ind=dic[rev[i]][-1]+1
st[ind-1]='-'
dic[rev[i]].pop()
su=fun1(ind,li)
ans+=(max(ind-su-j-1+pas,0))
update(ind,1,li)
print(ans)
```
|
instruction
| 0
| 97,197
| 0
| 194,394
|
No
|
output
| 1
| 97,197
| 0
| 194,395
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string s. You have to reverse it — that is, the first letter should become equal to the last letter before the reversal, the second letter should become equal to the second-to-last letter before the reversal — and so on. For example, if your goal is to reverse the string "abddea", you should get the string "aeddba". To accomplish your goal, you can swap the neighboring elements of the string.
Your task is to calculate the minimum number of swaps you have to perform to reverse the given string.
Input
The first line contains one integer n (2 ≤ n ≤ 200 000) — the length of s.
The second line contains s — a string consisting of n lowercase Latin letters.
Output
Print one integer — the minimum number of swaps of neighboring elements you have to perform to reverse the string.
Examples
Input
5
aaaza
Output
2
Input
6
cbaabc
Output
0
Input
9
icpcsguru
Output
30
Note
In the first example, you have to swap the third and the fourth elements, so the string becomes "aazaa". Then you have to swap the second and the third elements, so the string becomes "azaaa". So, it is possible to reverse the string in two swaps.
Since the string in the second example is a palindrome, you don't have to do anything to reverse it.
Submitted Solution:
```
a=int(input())
b=str(input())
if a==len(b):
print(b[::-1])
else:
pass
```
|
instruction
| 0
| 97,198
| 0
| 194,396
|
No
|
output
| 1
| 97,198
| 0
| 194,397
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,655
| 0
| 195,310
|
"Correct Solution:
```
n = int(input())
a = list(input())
b = list(set(a))
ans = 1
for i in b:
ans %= 10**9+7
ans *= a.count(i)+1
print((ans-1)%(10**9+7))
```
|
output
| 1
| 97,655
| 0
| 195,311
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,656
| 0
| 195,312
|
"Correct Solution:
```
_,s=open(0);a=1
for i in set(s):a*=s.count(i)+1
print(a//2%(10**9+7)-1)
```
|
output
| 1
| 97,656
| 0
| 195,313
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,657
| 0
| 195,314
|
"Correct Solution:
```
n=int(input())
s=input()
cnt=[0]*26
for i in s:cnt[ord(i)-ord('a')]+=1
mo=10**9+7
r=1
for i in cnt:
r*=i+1
r%=mo
print((r-1+mo)%mo)
```
|
output
| 1
| 97,657
| 0
| 195,315
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,658
| 0
| 195,316
|
"Correct Solution:
```
N=int(input())
X=[0 for i in range(26)]
S=input()
for i in S:
X[ord(i)-97]+=1
ans=1
P=10**9+7
for i in X:
ans=ans*(i+1)
ans%=P
ans-=1
print(ans)
```
|
output
| 1
| 97,658
| 0
| 195,317
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,659
| 0
| 195,318
|
"Correct Solution:
```
N = int(input())
S = input()
ans = 1
for c in range(ord('a'), ord('z') + 1):
ans *= S.count(chr(c)) + 1
print((ans-1) % (10**9 + 7))
```
|
output
| 1
| 97,659
| 0
| 195,319
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,660
| 0
| 195,320
|
"Correct Solution:
```
from collections import Counter
n = int(input())
S = input()
mod = 10**9+7
n = Counter(S)
ans = 1
for i, j in n.items():
ans *= (j+1)
print((ans-1)%mod)
```
|
output
| 1
| 97,660
| 0
| 195,321
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,661
| 0
| 195,322
|
"Correct Solution:
```
from collections import Counter
n=int(input())
s=input()
S=Counter(s)
ans=1
for i in S.values():
ans *=i+1
print((ans-1)%(10**9+7))
```
|
output
| 1
| 97,661
| 0
| 195,323
|
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
|
instruction
| 0
| 97,662
| 0
| 195,324
|
"Correct Solution:
```
MOD=10**9+7
N=int(input())
S=input()
cnt=[0]*26
for x in S:
cnt[ord(x)-97]+=1
res=1
for i in range(26):
res=res*(cnt[i]+1)%MOD
print(res-1)
```
|
output
| 1
| 97,662
| 0
| 195,325
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
n,s=open(0);a=1
for c in set(s.strip()):a*=s.count(c)+1
print(~-a%(10**9+7))
```
|
instruction
| 0
| 97,663
| 0
| 195,326
|
Yes
|
output
| 1
| 97,663
| 0
| 195,327
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
cnt = [0] * 26
n = int(input())
s = input()
for c in s:
cnt[ord(c) - ord('a')] += 1
res = 1
for i in cnt:
res *= i + 1
print((res - 1) % (10 ** 9 + 7))
```
|
instruction
| 0
| 97,664
| 0
| 195,328
|
Yes
|
output
| 1
| 97,664
| 0
| 195,329
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
n=int(input())
s=input()
mod=10**9+7
t=dict()
for c in s:
t.setdefault(c,1)
t[c]+=1
ans=1
for v in t.values():
ans=ans*v%mod
print(ans-1)
```
|
instruction
| 0
| 97,665
| 0
| 195,330
|
Yes
|
output
| 1
| 97,665
| 0
| 195,331
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
from collections import Counter
n,s=int(input()),input();c=[s[i]for i in range(n)];a=Counter(c);ans=1
for i in a:ans*=a[i]+1
print((ans-1)%(10**9+7))
```
|
instruction
| 0
| 97,666
| 0
| 195,332
|
Yes
|
output
| 1
| 97,666
| 0
| 195,333
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
import string
n = int(input())
s = input()
total = 2**n-1
k = 0
for i in string.ascii_lowercase:
c = s.count(i)
if c > 1:
l = 2**(n-c)
total -= l
k += c - 1
if k > 1:
total += k
print(total)
```
|
instruction
| 0
| 97,667
| 0
| 195,334
|
No
|
output
| 1
| 97,667
| 0
| 195,335
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
N = int(input())
S = input()
ans = 1
for c in [chr(x) for x in range(97, 97 + 26)]:
ans *= S.count(c) + 1
print(ans - 1)
```
|
instruction
| 0
| 97,668
| 0
| 195,336
|
No
|
output
| 1
| 97,668
| 0
| 195,337
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
N = int(input())
S = input()
iD = 10**9+7
aT={}
for s in S:
if s in aT:
aT[s]+=1
else:
aT[s]=1
iRes = (2**N) - 1
iC = 0
iC2 = 0
for s in aT:
iT = aT[s]
if 1 < iT:
iRes -= 2**(N-iT)
if 0 < iC :
iC2 += 2**(N-iC -iT)
iRes += iC2
iC += iT
print(iRes % iD)
```
|
instruction
| 0
| 97,669
| 0
| 195,338
|
No
|
output
| 1
| 97,669
| 0
| 195,339
|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a string S of length N. Among its subsequences, count the ones such that all characters are different, modulo 10^9+7. Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
* 1 \leq N \leq 100000
* S consists of lowercase English letters.
* |S|=N
Input
Input is given from Standard Input in the following format:
N
S
Output
Print the number of the subsequences such that all characters are different, modulo 10^9+7.
Examples
Input
4
abcd
Output
15
Input
3
baa
Output
5
Input
5
abcab
Output
17
Submitted Solution:
```
if __name__ == '__main__':
mod = 10**9 +7
N = int(input())
S = str(input())
letter = defaultdict(int)
for i in range(N):
letter[S[i]] += 1
count = 1
for c in letter:
count *= (letter[c]+1)
count%mod
print(count-1)
```
|
instruction
| 0
| 97,670
| 0
| 195,340
|
No
|
output
| 1
| 97,670
| 0
| 195,341
|
Provide a correct Python 3 solution for this coding contest problem.
Problem statement
Given the string $ S $. Find the number of all anagrams in $ S $ that are palindromic.
An anagram of the string $ X $ is an anagram of $ Y $, which means that $ X $ is equal to $ Y $, or that the rearranged characters of $ X $ are equal to $ Y $. For example, for the string abcd, abcd and cbda are anagrams, but abed, cab and abcdd are not anagrams.
When the string $ X $ is a palindrome, it means that the reverse reading of $ X $ is equal to $ X $ itself. For example, abc and ab are not palindromes, and a and abccba are palindromes.
Constraint
* $ 1 \ leq | S | \ leq 40 $ ($ | S | $ is the length of the string $ S $)
* $ S $ contains only lowercase letters.
* The answer is guaranteed to be less than $ 2 ^ {63} $.
input
Input follows the following format.
$ S $
output
Output the number on one line.
Examples
Input
ab
Output
0
Input
abba
Output
2
|
instruction
| 0
| 97,792
| 0
| 195,584
|
"Correct Solution:
```
from collections import Counter
import math
s = input()
dic = Counter(s)
n_odd = 0
for c in dic:
if dic[c] & 1:
n_odd += 1
if n_odd > 1:
print(0)
exit()
dic[c] -= 1
ans = math.factorial(len(s) // 2)
for num in dic.values():
ans //= math.factorial(num // 2)
print(ans)
```
|
output
| 1
| 97,792
| 0
| 195,585
|
Provide a correct Python 3 solution for this coding contest problem.
Problem statement
Given the string $ S $. Find the number of all anagrams in $ S $ that are palindromic.
An anagram of the string $ X $ is an anagram of $ Y $, which means that $ X $ is equal to $ Y $, or that the rearranged characters of $ X $ are equal to $ Y $. For example, for the string abcd, abcd and cbda are anagrams, but abed, cab and abcdd are not anagrams.
When the string $ X $ is a palindrome, it means that the reverse reading of $ X $ is equal to $ X $ itself. For example, abc and ab are not palindromes, and a and abccba are palindromes.
Constraint
* $ 1 \ leq | S | \ leq 40 $ ($ | S | $ is the length of the string $ S $)
* $ S $ contains only lowercase letters.
* The answer is guaranteed to be less than $ 2 ^ {63} $.
input
Input follows the following format.
$ S $
output
Output the number on one line.
Examples
Input
ab
Output
0
Input
abba
Output
2
|
instruction
| 0
| 97,793
| 0
| 195,586
|
"Correct Solution:
```
import collections
from math import *
s=input()
a=collections.Counter(s)
o=0
for x in a:
if a[x]&1:
o+=1
if o>1:print(0);break
a[x]-=1
else:
b=factorial(len(s)//2)
for x in a.values():
b//=factorial(x//2)
print(b)
```
|
output
| 1
| 97,793
| 0
| 195,587
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given two integers n and k.
Your task is to construct such a string s of length n that for each i from 1 to k there is at least one i-th letter of the Latin alphabet in this string (the first letter is 'a', the second is 'b' and so on) and there are no other letters except these. You have to maximize the minimal frequency of some letter (the frequency of a letter is the number of occurrences of this letter in a string). If there are several possible answers, you can print any.
You have to answer t independent queries.
Input
The first line of the input contains one integer t (1 ≤ t ≤ 100) — the number of queries.
The next t lines are contain queries, one per line. The i-th line contains two integers n_i and k_i (1 ≤ n_i ≤ 100, 1 ≤ k_i ≤ min(n_i, 26)) — the length of the string in the i-th query and the number of characters in the i-th query.
Output
Print t lines. In the i-th line print the answer to the i-th query: any string s_i satisfying the conditions in the problem statement with constraints from the i-th query.
Example
Input
3
7 3
4 4
6 2
Output
cbcacab
abcd
baabab
Note
In the first example query the maximum possible minimal frequency is 2, it can be easily seen that the better answer doesn't exist. Other examples of correct answers: "cbcabba", "ccbbaaa" (any permutation of given answers is also correct).
In the second example query any permutation of first four letters is acceptable (the maximum minimal frequency is 1).
In the third example query any permutation of the given answer is acceptable (the maximum minimal frequency is 3).
|
instruction
| 0
| 97,858
| 0
| 195,716
|
Tags: implementation
Correct Solution:
```
s = 'abcdefghijklmnopqrstuvwxyz'
for _ in range(int(input())):
n, k = list(map(int, input().strip().split()))
q = n//k
rem = n % k
print(s[:k]*q + s[:rem])
```
|
output
| 1
| 97,858
| 0
| 195,717
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given two integers n and k.
Your task is to construct such a string s of length n that for each i from 1 to k there is at least one i-th letter of the Latin alphabet in this string (the first letter is 'a', the second is 'b' and so on) and there are no other letters except these. You have to maximize the minimal frequency of some letter (the frequency of a letter is the number of occurrences of this letter in a string). If there are several possible answers, you can print any.
You have to answer t independent queries.
Input
The first line of the input contains one integer t (1 ≤ t ≤ 100) — the number of queries.
The next t lines are contain queries, one per line. The i-th line contains two integers n_i and k_i (1 ≤ n_i ≤ 100, 1 ≤ k_i ≤ min(n_i, 26)) — the length of the string in the i-th query and the number of characters in the i-th query.
Output
Print t lines. In the i-th line print the answer to the i-th query: any string s_i satisfying the conditions in the problem statement with constraints from the i-th query.
Example
Input
3
7 3
4 4
6 2
Output
cbcacab
abcd
baabab
Note
In the first example query the maximum possible minimal frequency is 2, it can be easily seen that the better answer doesn't exist. Other examples of correct answers: "cbcabba", "ccbbaaa" (any permutation of given answers is also correct).
In the second example query any permutation of first four letters is acceptable (the maximum minimal frequency is 1).
In the third example query any permutation of the given answer is acceptable (the maximum minimal frequency is 3).
|
instruction
| 0
| 97,859
| 0
| 195,718
|
Tags: implementation
Correct Solution:
```
t = int(input())
alp = list('abcdefghijklmnopqrstuvwxyz')
for i in range(t):
n, k = tuple(map(int, input().split()))
j = 0
s = ''
while len(s) != n:
s += alp[j]
if j == k - 1:
j = -1
j += 1
print(s)
```
|
output
| 1
| 97,859
| 0
| 195,719
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given two integers n and k.
Your task is to construct such a string s of length n that for each i from 1 to k there is at least one i-th letter of the Latin alphabet in this string (the first letter is 'a', the second is 'b' and so on) and there are no other letters except these. You have to maximize the minimal frequency of some letter (the frequency of a letter is the number of occurrences of this letter in a string). If there are several possible answers, you can print any.
You have to answer t independent queries.
Input
The first line of the input contains one integer t (1 ≤ t ≤ 100) — the number of queries.
The next t lines are contain queries, one per line. The i-th line contains two integers n_i and k_i (1 ≤ n_i ≤ 100, 1 ≤ k_i ≤ min(n_i, 26)) — the length of the string in the i-th query and the number of characters in the i-th query.
Output
Print t lines. In the i-th line print the answer to the i-th query: any string s_i satisfying the conditions in the problem statement with constraints from the i-th query.
Example
Input
3
7 3
4 4
6 2
Output
cbcacab
abcd
baabab
Note
In the first example query the maximum possible minimal frequency is 2, it can be easily seen that the better answer doesn't exist. Other examples of correct answers: "cbcabba", "ccbbaaa" (any permutation of given answers is also correct).
In the second example query any permutation of first four letters is acceptable (the maximum minimal frequency is 1).
In the third example query any permutation of the given answer is acceptable (the maximum minimal frequency is 3).
|
instruction
| 0
| 97,860
| 0
| 195,720
|
Tags: implementation
Correct Solution:
```
num=int(input())
alph="abcdefghijklmnopqrstuvwxyz"
while num:
a=[]
r=[]
n,k=map(int,input().split())
f=int(n/k)
for i in range(k):
a.append(alph[i])
for i in range(len(a)):
for j in range(f):
r.append(a[i])
while len(r)!=n:
r.append(a[k-1])
print("".join(r))
num-=1
```
|
output
| 1
| 97,860
| 0
| 195,721
|
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given two integers n and k.
Your task is to construct such a string s of length n that for each i from 1 to k there is at least one i-th letter of the Latin alphabet in this string (the first letter is 'a', the second is 'b' and so on) and there are no other letters except these. You have to maximize the minimal frequency of some letter (the frequency of a letter is the number of occurrences of this letter in a string). If there are several possible answers, you can print any.
You have to answer t independent queries.
Input
The first line of the input contains one integer t (1 ≤ t ≤ 100) — the number of queries.
The next t lines are contain queries, one per line. The i-th line contains two integers n_i and k_i (1 ≤ n_i ≤ 100, 1 ≤ k_i ≤ min(n_i, 26)) — the length of the string in the i-th query and the number of characters in the i-th query.
Output
Print t lines. In the i-th line print the answer to the i-th query: any string s_i satisfying the conditions in the problem statement with constraints from the i-th query.
Example
Input
3
7 3
4 4
6 2
Output
cbcacab
abcd
baabab
Note
In the first example query the maximum possible minimal frequency is 2, it can be easily seen that the better answer doesn't exist. Other examples of correct answers: "cbcabba", "ccbbaaa" (any permutation of given answers is also correct).
In the second example query any permutation of first four letters is acceptable (the maximum minimal frequency is 1).
In the third example query any permutation of the given answer is acceptable (the maximum minimal frequency is 3).
|
instruction
| 0
| 97,861
| 0
| 195,722
|
Tags: implementation
Correct Solution:
```
alphabet = 'abcdefghijklmnopqrstuvwxyz'
t = int(input())
for i in range(t):
x, y = list(map(int, input().split()))
k = x // y
s = ''
for i in range(k):
s += alphabet[:y]
k = x % y
if k != 0:
s += alphabet[:k]
print(s)
```
|
output
| 1
| 97,861
| 0
| 195,723
|
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