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 |
|---|---|---|---|---|---|
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
And where the are the phone numbers?
You are given a string s consisting of lowercase English letters and an integer k. Find the lexicographically smallest string t of length k, such that its set of letters is a subset of the set of letters of s and s is lexicographically smaller than t.
It's guaranteed that the answer exists.
Note that the set of letters is a set, not a multiset. For example, the set of letters of abadaba is {a, b, d}.
String p is lexicographically smaller than string q, if p is a prefix of q, is not equal to q or there exists i, such that pi < qi and for all j < i it is satisfied that pj = qj. For example, abc is lexicographically smaller than abcd , abd is lexicographically smaller than abec, afa is not lexicographically smaller than ab and a is not lexicographically smaller than a.
Input
The first line of input contains two space separated integers n and k (1 ≤ n, k ≤ 100 000) — the length of s and the required length of t.
The second line of input contains the string s consisting of n lowercase English letters.
Output
Output the string t conforming to the requirements above.
It's guaranteed that the answer exists.
Examples
Input
3 3
abc
Output
aca
Input
3 2
abc
Output
ac
Input
3 3
ayy
Output
yaa
Input
2 3
ba
Output
baa
Note
In the first example the list of strings t of length 3, such that the set of letters of t is a subset of letters of s is as follows: aaa, aab, aac, aba, abb, abc, aca, acb, .... Among them, those are lexicographically greater than abc: aca, acb, .... Out of those the lexicographically smallest is aca.
Submitted Solution:
```
n,k=map(int,input().split())
s=list(input())
m=list(set(s));m.sort()
l=[];co=0
if k<=n:
z=s[:k+1]
for i in range(1,k+1):
if ord(z[-i])>ord(z[-i-1]):
for j in m:
if ord(z[-i-1])<ord(j):
z[-i-1]=j
co=1;break
if co==1:
break
l=z[:k-i+1]
print(''.join(l)+m[0]*(k-len(l)))
else:
print(''.join(s)+m[0]*(k-n))
``` | instruction | 0 | 51,055 | 0 | 102,110 |
No | output | 1 | 51,055 | 0 | 102,111 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
And where the are the phone numbers?
You are given a string s consisting of lowercase English letters and an integer k. Find the lexicographically smallest string t of length k, such that its set of letters is a subset of the set of letters of s and s is lexicographically smaller than t.
It's guaranteed that the answer exists.
Note that the set of letters is a set, not a multiset. For example, the set of letters of abadaba is {a, b, d}.
String p is lexicographically smaller than string q, if p is a prefix of q, is not equal to q or there exists i, such that pi < qi and for all j < i it is satisfied that pj = qj. For example, abc is lexicographically smaller than abcd , abd is lexicographically smaller than abec, afa is not lexicographically smaller than ab and a is not lexicographically smaller than a.
Input
The first line of input contains two space separated integers n and k (1 ≤ n, k ≤ 100 000) — the length of s and the required length of t.
The second line of input contains the string s consisting of n lowercase English letters.
Output
Output the string t conforming to the requirements above.
It's guaranteed that the answer exists.
Examples
Input
3 3
abc
Output
aca
Input
3 2
abc
Output
ac
Input
3 3
ayy
Output
yaa
Input
2 3
ba
Output
baa
Note
In the first example the list of strings t of length 3, such that the set of letters of t is a subset of letters of s is as follows: aaa, aab, aac, aba, abb, abc, aca, acb, .... Among them, those are lexicographically greater than abc: aca, acb, .... Out of those the lexicographically smallest is aca.
Submitted Solution:
```
import math
n, k = map(int, input().split())
s = input()
alfa = [0 for i in range(26)]
set = []
for i in s:
if alfa[ord(i) - 97] == 0:
set.append(i)
alfa[ord(i) - 97]+=1
# print("abasbcc" < "")
set = sorted(set)
# print(set)
change = False
if n < k:
news = ''
news = s
news+= set[0]*(k-n)
print(news)
elif n > k:
newv =[]
ind = k-1
ultima = s[ind]
# news = s[0: k-1]
while change == False:
if ultima == set[len(set)-1]:
ind -=1
ultima = s[ind]
else:
for i in range(len(set)):
if set[i] == ultima:
ultima = set[i+1]
change = True
break
# news[ind] = ultima
# print(ultima)
for i in range(0, ind):
newv.append(s[i])
newv.append(ultima)
for i in range(ind+1, k-ind):
newv.append(s[i])
for i in range(len(newv)):
print(newv[i], end='')
print()
else:
flag = False
ultima = ''
for i in range(n-1, -1, -1):
# print("oi")
novov = ''
ultimo = i
if s[i] != set[len(set)-1]:
# print(i)
for j in range(len(set)):
if set[j] == s[i]:
ultima = set[j+1]
flag = True
break
if flag:
novov += s[0:i]
novov += ultima
# print(novov)
# print(i)
# print(k)
novov += set[0]*(k-1-i)
print(novov)
break
# ayy
# addcd
# cdd
# print(set)
``` | instruction | 0 | 51,056 | 0 | 102,112 |
No | output | 1 | 51,056 | 0 | 102,113 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
And where the are the phone numbers?
You are given a string s consisting of lowercase English letters and an integer k. Find the lexicographically smallest string t of length k, such that its set of letters is a subset of the set of letters of s and s is lexicographically smaller than t.
It's guaranteed that the answer exists.
Note that the set of letters is a set, not a multiset. For example, the set of letters of abadaba is {a, b, d}.
String p is lexicographically smaller than string q, if p is a prefix of q, is not equal to q or there exists i, such that pi < qi and for all j < i it is satisfied that pj = qj. For example, abc is lexicographically smaller than abcd , abd is lexicographically smaller than abec, afa is not lexicographically smaller than ab and a is not lexicographically smaller than a.
Input
The first line of input contains two space separated integers n and k (1 ≤ n, k ≤ 100 000) — the length of s and the required length of t.
The second line of input contains the string s consisting of n lowercase English letters.
Output
Output the string t conforming to the requirements above.
It's guaranteed that the answer exists.
Examples
Input
3 3
abc
Output
aca
Input
3 2
abc
Output
ac
Input
3 3
ayy
Output
yaa
Input
2 3
ba
Output
baa
Note
In the first example the list of strings t of length 3, such that the set of letters of t is a subset of letters of s is as follows: aaa, aab, aac, aba, abb, abc, aca, acb, .... Among them, those are lexicographically greater than abc: aca, acb, .... Out of those the lexicographically smallest is aca.
Submitted Solution:
```
n, k = [int(f) for f in input().split(' ') if f]
s = input()
minChar = 256
for i in range(n):
minChar = min(minChar, ord(s[i]))
minChar = chr(minChar)
for i in range(k):
print(minChar, end='')
``` | instruction | 0 | 51,057 | 0 | 102,114 |
No | output | 1 | 51,057 | 0 | 102,115 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
And where the are the phone numbers?
You are given a string s consisting of lowercase English letters and an integer k. Find the lexicographically smallest string t of length k, such that its set of letters is a subset of the set of letters of s and s is lexicographically smaller than t.
It's guaranteed that the answer exists.
Note that the set of letters is a set, not a multiset. For example, the set of letters of abadaba is {a, b, d}.
String p is lexicographically smaller than string q, if p is a prefix of q, is not equal to q or there exists i, such that pi < qi and for all j < i it is satisfied that pj = qj. For example, abc is lexicographically smaller than abcd , abd is lexicographically smaller than abec, afa is not lexicographically smaller than ab and a is not lexicographically smaller than a.
Input
The first line of input contains two space separated integers n and k (1 ≤ n, k ≤ 100 000) — the length of s and the required length of t.
The second line of input contains the string s consisting of n lowercase English letters.
Output
Output the string t conforming to the requirements above.
It's guaranteed that the answer exists.
Examples
Input
3 3
abc
Output
aca
Input
3 2
abc
Output
ac
Input
3 3
ayy
Output
yaa
Input
2 3
ba
Output
baa
Note
In the first example the list of strings t of length 3, such that the set of letters of t is a subset of letters of s is as follows: aaa, aab, aac, aba, abb, abc, aca, acb, .... Among them, those are lexicographically greater than abc: aca, acb, .... Out of those the lexicographically smallest is aca.
Submitted Solution:
```
import sys,copy
def main():
p1 = sys.stdin.readline()
if p1 == '':
return
n,k = map(int,p1.split(' '))
p2 = sys.stdin.readline().strip('\n')
list1 = list(p2)
list2 = copy.deepcopy(list1)
list2.sort()
min = list2[0]
max = list2[-1]
if n < k:
for i in range(len(list1)):
print(list1[i],end = '')
for i in range(len(list1), k):
print(min,end = '')
else:
for i in range(len(list1) - 1,-1,-1):
if max > list1[i]:
temp = i
break
for i in range(temp):
print(list1[i],end='')
i = list2.index(list1[temp])
for j in range(i,len(list2)):
if list1[temp] < list2[j]:
print(list2[j],end='')
break
for i in range(temp + 1,k):
print(min,end='')
if __name__ == '__main__':
main()
``` | instruction | 0 | 51,058 | 0 | 102,116 |
No | output | 1 | 51,058 | 0 | 102,117 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,059 | 0 | 102,118 |
"Correct Solution:
```
k = int(input())
s = input()
n = len(s)
mod = 10**9 + 7
m = [1]*(k+1)
M = [1]*(k+1)
h = [1]*(k+1)
for i in range(k):
m[i+1] = (m[i] * 25)%mod
M[i+1] = (M[i] * 26)%mod
h[i+1] = (h[i]*(n+i)*pow(i+1,mod-2,mod))%mod
ans = 0
for i in range(k+1):
ans += m[i]*M[k-i]%mod*h[i]%mod
ans %= mod
print(ans)
``` | output | 1 | 51,059 | 0 | 102,119 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,060 | 0 | 102,120 |
"Correct Solution:
```
K = int(input())
S = input()
N = len(S)
MOD = 10 ** 9 + 7
# 逆元の前計算
factorial = [1, 1]
inverse = [1, 1]
invere_base = [0, 1]
for i in range(2, K + N + 1):
factorial.append((factorial[-1] * i) % MOD)
invere_base.append((-invere_base[MOD % i] * (MOD // i)) % MOD)
inverse.append((inverse[-1] * invere_base[-1]) % MOD)
def nCr(n, r):
if (r < 0 or r > n):
return 0
r = min(r, n - r)
return factorial[n] * inverse[r] * inverse[n - r] % MOD
ans = 0
for i in range(K + 1):
ans += pow(25, i, MOD) * nCr(i + N - 1, N - 1) * pow(26, K - i, MOD) % MOD
ans %= MOD
print(ans % MOD)
``` | output | 1 | 51,060 | 0 | 102,121 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,061 | 0 | 102,122 |
"Correct Solution:
```
K = int(input())
S = input()
m = 1000000007
def make_factorial_table(n):
result = [0] * (n + 1)
result[0] = 1
for i in range(1, n + 1):
result[i] = result[i - 1] * i % m
return result
def mcomb(n, k):
if n == 0 and k == 0:
return 1
if n < k or k < 0:
return 0
return fac[n] * pow(fac[n - k], m - 2, m) * pow(fac[k], m - 2, m) % m
fac = make_factorial_table(len(S) - 1 + K)
result = 0
for i in range(K + 1):
t = pow(26, i, m) * mcomb(len(S) - 1 + K - i, len(S) - 1)
t %= m
t *= pow(25, K - i, m)
t %= m
result += t
result %= m
print(result)
``` | output | 1 | 51,061 | 0 | 102,123 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,062 | 0 | 102,124 |
"Correct Solution:
```
K=int(input())
S=input()
N=len(S)
mod=10**9+7
fact=[1]*(K+N)
for i in range(2,K+N):
fact[i]=fact[i-1]*i%mod
inv=[1]*(K+N)
inv[K+N-1]=pow(fact[K+N-1],mod-2,mod)
for i in range(K+N-2,0,-1):
inv[i]=inv[i+1]*(i+1)%mod
def comb(n,r):
ret=fact[n]*inv[r]*inv[n-r]%mod
return ret
ans=0
for i in range(K+1):
ans+=pow(26,i,mod)*pow(25,K-i,mod)*comb(K+N-1-i,N-1)
ans%=mod
print(ans)
``` | output | 1 | 51,062 | 0 | 102,125 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,063 | 0 | 102,126 |
"Correct Solution:
```
K=int(input())
S=input()
mod=10**9+7
def inv(x):
return pow(x,mod-2,mod)
N=len(S)
ans=0
tmp1=1
tmp2=1
for i in range(0,K+1):
ans=ans+(tmp1*tmp2)
ans%=mod
tmp1=tmp1*25
tmp1%=mod
tmp2=tmp2*(inv(i+1)*(N+K-i))
tmp2%=mod
#print(tmp1,tmp2)
print(ans)
``` | output | 1 | 51,063 | 0 | 102,127 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,064 | 0 | 102,128 |
"Correct Solution:
```
def prepare(n, MOD):
f = 1
factorials = [1]
for m in range(1, n + 1):
f *= m
f %= MOD
factorials.append(f)
inv = pow(f, MOD - 2, MOD)
invs = [1] * (n + 1)
invs[n] = inv
for m in range(n, 1, -1):
inv *= m
inv %= MOD
invs[m - 1] = inv
return factorials, invs
k = int(input())
s = input()
l = len(s)
MOD = 10 ** 9 + 7
facts, finvs = prepare(k + l, MOD)
ans = 0
for i in range(k + 1):
r = k - i
pat = facts[l + r - 1] * finvs[l - 1] * finvs[r] % MOD
ans = (ans + pat * pow(25, r, MOD) * pow(26, i, MOD)) % MOD
print(ans)
``` | output | 1 | 51,064 | 0 | 102,129 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,065 | 0 | 102,130 |
"Correct Solution:
```
k=int(input())
s=len(input())
def cmb(n,r,mod):
if r<0 or n<r:
return 0
r=min(r,n-r)
return g1[n]*g2[r]*g2[n-r]%mod
mod=10**9+7
g1=[1,1]#元table
g2=[1,1]#逆元table
inv=[0,1]#逆元table計算用
for i in range(2,k+s+1):
g1.append(g1[-1]*i%mod)
inv.append(-inv[mod%i]*(mod//i)%mod)
g2.append(g2[-1]*inv[-1]%mod)
ans=1
for i in range(1,k+1):
ans=(ans*26+cmb(i+s-1,s-1,mod)*pow(25,i,mod))%mod
print(ans)
``` | output | 1 | 51,065 | 0 | 102,131 |
Provide a correct Python 3 solution for this coding contest problem.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117 | instruction | 0 | 51,066 | 0 | 102,132 |
"Correct Solution:
```
k = int(input())
n = len(input())
p = 10**9 + 7
a = 1
fct = [a]
for i in range(1, n + k + 1):
a = (a * i) % p
fct.append(a)
b = pow(fct[-1], p - 2, p)
inv = [b]
for i in range(1, n + k + 1)[::-1]:
b = (b * i) % p
inv.append(b)
inv.reverse()
ans = 0
pow25, pow26 = [1], [1]
for i in range(1, k + 1):
pow25.append((pow25[-1] * 25) % p)
pow26.append((pow26[-1] * 26) % p)
for i in range(k + 1):
c = fct[i + n - 1] * inv[i] * inv[n - 1]
ans += pow25[i] * pow26[k - i] * c
ans %= p
print(ans)
``` | output | 1 | 51,066 | 0 | 102,133 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
k = int(input())
s = input()
mod=10**9+7
n=len(s)
framod=[1]
def framod_calc(n, mod, a=1):
for i in range(1,n+1):
a=a * i % mod
framod.append(a)
framod_calc(n+k+1, mod)
def combmod(n, k, mod):
a=framod[n]
b=framod[k]
c=framod[n-k]
return (a * pow(b, mod-2, mod) * pow(c, mod-2, mod)) % mod
ans=0
for i in range(k+1):
ans+=(pow(26, i, mod)*pow(25, k-i, mod))*combmod(n+(k-i)-1, n-1, mod)
ans%=mod
print(ans)
``` | instruction | 0 | 51,068 | 0 | 102,136 |
Yes | output | 1 | 51,068 | 0 | 102,137 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
mod=10**9+7
k=int(input())
s=input()
n=len(s)
c=1
t=1
ans=0
m=10**20
for i in range(k+1):
ans+=c*t
if ans>m:ans%=mod
c*=(n+k-i)*pow(i+1,mod-2,mod)
if c>m:c%=mod
t*=25
if t>m:t%=mod
print(ans%mod)
``` | instruction | 0 | 51,069 | 0 | 102,138 |
Yes | output | 1 | 51,069 | 0 | 102,139 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
def nCr(n,r,fac,finv):
mod = (10**9)+7
ans = fac[n] * (finv[r] * finv[n-r] % mod) % mod
return ans
k = int(input())
s = input()
l = len(s)
n = l+k+1
# als = list(map(int,input().split()))
# als.sort()
ans = 0
mod = (10**9)+7
fac = [1,1]+[0]*n
finv = [1,1]+[0]*n
inv = [1,1]+[0]*n
for i in range(2,n+1):
fac[i] = fac[i-1] * i % mod
inv[i] = mod - inv[mod%i] * (mod//i) % mod
finv[i] = finv[i-1] * inv[i] % mod
for i in range(k+1):
ans += nCr(l-i+k-1,l-1,fac,finv)*pow(26,i,mod)*pow(25,k-i,mod)
ans %= mod
print(ans)
``` | instruction | 0 | 51,070 | 0 | 102,140 |
Yes | output | 1 | 51,070 | 0 | 102,141 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
from collections import defaultdict, deque, Counter
from heapq import heappush, heappop, heapify
import math
import bisect
import random
from itertools import permutations, accumulate, combinations, product
import sys
import string
from bisect import bisect_left, bisect_right
from math import factorial, ceil, floor, gcd
from operator import mul
from functools import reduce
from operator import mul
import pprint
sys.setrecursionlimit(2147483647)
INF = 10 ** 20
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def I(): return int(sys.stdin.buffer.readline())
def LS(): return sys.stdin.buffer.readline().rstrip().decode('utf-8').split()
def S(): return sys.stdin.buffer.readline().rstrip().decode('utf-8')
def IR(n): return [I() for i in range(n)]
def LIR(n): return [LI() for i in range(n)]
def SR(n): return [S() for i in range(n)]
def LSR(n): return [LS() for i in range(n)]
def SRL(n): return [list(S()) for i in range(n)]
def MSRL(n): return [[int(j) for j in list(S())] for i in range(n)]
mod = 1000000007
k = I()
s = S()
l = len(s)
n = k + s + 1
fac = [1] * (n + 1)
inv = [1] * (n + 1)
twentyFive = [1] * (n + 1)
twentySix = [1] * (n + 1)
for j in range(1, n + 1):
fac[j] = fac[j-1] * j % mod
twentyFive[j] = twentyFive[j - 1] * 25 % mod
twentySix[j] = twentySix[j - 1] * 26 % mod
inv[n] = pow(fac[n], mod-2, mod)
for j in range(n-1, -1, -1):
inv[j] = inv[j+1] * (j+1) % mod
def comb(n, r):
if r > n or n < 0 or r < 0:
return 0
return fac[n] * inv[n - r] * inv[r] % mod
ans = 0
for i in range(k + 1):
ans += comb(l - 1 + i, i) * twentyFive[i] % mod * twentySix[k - i] % mod
ans %= mod
print(ans)
``` | instruction | 0 | 51,071 | 0 | 102,142 |
No | output | 1 | 51,071 | 0 | 102,143 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
K = int(input())
S =input()
def cmb(n,r,p):
if(r<0) or (n<r):
return 0
r = min(r,n-r)
return fact[n]*factinv[r]*factinv[n-r]%p
p = 10 ** 9 + 7
N = 10**6+3
fact = [1] * ( N + 3)
factinv = [1] * (N + 3)
inv = [0]* (N + 3)
inv[1] = 1
for i in range(2,N+1):
fact[i] = fact[i-1] * i % p
inv[i] = p-inv[p % i] * (p//i) % p
factinv[i] = factinv[i-1] * inv[i] % p
def powmod(a,n,mod):
res = 1
while n > 0:
if n & 1:
res = res * a % mod
a = a * a % mod
n>>=1
return res
ss = len(S)
ans = 0
k = 1;
for i in range(K+1):
ans += cmb(ss+K-i-1,ss-1,p) * k * powmod(25,K-i,p)
ans %= p
k = k * 26 % p
print(ans)
``` | instruction | 0 | 51,072 | 0 | 102,144 |
No | output | 1 | 51,072 | 0 | 102,145 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
import os
import heapq
import sys
import math
import operator
from collections import defaultdict
from io import BytesIO, IOBase
"""def gcd(a,b):
if b==0:
return a
else:
return gcd(b,a%b)"""
# def pw(a,b):
# result=1
# while(b>0):
# if(b%2==1): result*=a
# a*=a
# b//=2
# return result
def ncr(n, r, p):
num = den = 1
for i in range(r):
num = (num * (n - i)) % p
den = (den * (i + 1)) % p
return (num * pow(den, p - 2, p)) % p
def inpt():
return [int(k) for k in input().split()]
def main():
k = int(input())
s = input()
n = len(s)
ans = 0
md = 10 ** 9 + 7
for i in range(k + 1):
ans += (ncr(n + k - i - 1, n - 1, md) * (pow(26, i, md)) % md * pow(25, k - i, md)) % md
ans %= md
print(ans)
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")
if __name__ == "__main__":
main()
``` | instruction | 0 | 51,073 | 0 | 102,146 |
No | output | 1 | 51,073 | 0 | 102,147 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
How many strings can be obtained by applying the following operation on a string S exactly K times: "choose one lowercase English letter and insert it somewhere"?
The answer can be enormous, so print it modulo (10^9+7).
Constraints
* K is an integer between 1 and 10^6 (inclusive).
* S is a string of length between 1 and 10^6 (inclusive) consisting of lowercase English letters.
Input
Input is given from Standard Input in the following format:
K
S
Output
Print the number of strings satisfying the condition, modulo (10^9+7).
Examples
Input
5
oof
Output
575111451
Input
37564
whydidyoudesertme
Output
318008117
Submitted Solution:
```
import copy
def com(n,r,m):
#a = math.factorial(n)%m
a = 1
for i in range(1,n+1):
a *= i
a %= m
A = pow(a,m-2,m)
b= copy.copy(A)
for i in range(n,r,-1):
b = (b*i)%m
c = copy.copy(A)
for i in range(n,n-r,-1):
c = (c*i)%m
return (a*b*c)%m
def main():
k = int(input())
s = input()
mod = 10**9+7
z = [1]
for i in range(1,k+1):
y = z[-1]*26
z.append(y%mod)
#print(z)
l = len(s)
ans = 0
p = 1 #pow(25,i-len(s),mod)
q = z[k]
bai = 1
for i in range(l,l+k+1):
base = p*q #pow(26,len(s)+k-i,mod)
#base = pow(25,i-len(s),mod) * pow(26,len(s)+k-i,mod)
#bai = r
#bai = com(i-1,len(s)-1,mod)
#print(i,len(s),base,bai)
ans += base*bai
ans %= mod
p *= 25
p %= mod
q = z[l+k-i-1]
bai = bai*i*pow(i-l+1,mod-2,mod)
print(ans)
if __name__=="__main__":
main()
``` | instruction | 0 | 51,074 | 0 | 102,148 |
No | output | 1 | 51,074 | 0 | 102,149 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,075 | 0 | 102,150 |
"Correct Solution:
```
def i1():
return int(input())
def i2():
return [int(i) for i in input().split()]
import sys
sys.setrecursionlimit(10**6)
n=i1()
s=input()
q=i1()
N=0
while n:
n>>=1
N+=1
n=2**N
t=[0 for i in range(2*n-1)]
def ud(i,x):
i+=n-1
t[i]=x
while i:
i=(i-1)//2
t[i]=t[i*2+1] | t[i*2+2]
def qr(a,b,k,l,r):
if r<=a or b<=l:
return 0
elif a<=l and r<=b:
return t[k]
else:
return qr(a,b,k*2+1,l,(l+r)//2) | qr(a,b,k*2+2,(l+r)//2,r)
for i in range(len(s)):
ud(i,1<<(ord(s[i])-ord("a")))
while q:
[ty,i,c]=[i for i in input().split()]
ty=int(ty)
i=int(i)
if ty==1:
ud(i-1,1<<(ord(c)-ord("a")))
else:
c=int(c)
x=0
z=qr(i-1,c,0,0,n)
while z:
if z%2==1:
x+=1
z>>=1
print(x)
q-=1
``` | output | 1 | 51,075 | 0 | 102,151 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,076 | 0 | 102,152 |
"Correct Solution:
```
def RSQ_add(i, x, y):
while True:
if i > n:
break
BIT[y][i] += x
i += i & -i
def RSQ_getsum(i, x):
s = 0
while True:
if i <= 0:
break
s += BIT[x][i]
i -= i & -i
return s
n = int(input())
s = list(input())
q = int(input())
BIT = [[0] * (n + 1) for _ in range(26)]
for i in range(n):
y = ord(s[i]) - 97
RSQ_add(i + 1, 1, y)
for _ in range(q):
com, a, b = map(str, input().split())
com, a = int(com), int(a)
if com == 1:
RSQ_add(a, -1, ord(s[a - 1]) - 97)
RSQ_add(a, 1, ord(b) - 97)
s[a - 1] = b
else:
b = int(b)
ans = 0
for i in range(26):
if RSQ_getsum(b, i) - RSQ_getsum(a - 1, i) >= 1:
ans += 1
print(ans)
``` | output | 1 | 51,076 | 0 | 102,153 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,078 | 0 | 102,156 |
"Correct Solution:
```
def segfunc(x,y):
return set(x)|set(y)
ide_ele=set()
class SegTree():
def __init__(self,init_val,segfunc,ide_ele):
n=len(init_val)
self.segfunc=segfunc
self.ide_ele=ide_ele
self.num=1<<(n-1).bit_length()
self.tree=[ide_ele]*2*self.num
for i in range(n):
self.tree[self.num+i]=init_val[i]
for i in range(self.num-1,0,-1):
self.tree[i]=self.segfunc(self.tree[2*i], self.tree[2*i+1])
def update(self,k,x):
k+=self.num
self.tree[k]=x
while k>1:
self.tree[k>>1]=self.segfunc(self.tree[k],self.tree[k^1])
k>>=1
def query(self,l,r):
res=self.ide_ele
l+=self.num
r+=self.num
while l<r:
if l&1:
res=self.segfunc(res,self.tree[l])
l+=1
if r&1:
res=self.segfunc(res,self.tree[r-1])
l>>=1
r>>=1
return res
n=int(input())
s=input()
q=int(input())
st=SegTree(s,segfunc,ide_ele)
for _ in range(q):
q,c,r=input().split()
if q=='1':st.update(int(c)-1,r)
else:print(len(st.query(int(c)-1,int(r))))
``` | output | 1 | 51,078 | 0 | 102,157 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,079 | 0 | 102,158 |
"Correct Solution:
```
N = int(input())
A = [ord(a) - 97 for a in input()]
NN = 19
BIT=[[0]*(2**NN+1) for _ in range(26)]
def addbit(t, i, x):
while i <= 2**NN:
BIT[t][i] += x
i += i & (-i)
def getsum(t, i):
ret = 0
while i != 0:
ret += BIT[t][i]
i -= i&(-i)
return ret
for i, a in enumerate(A):
addbit(a, i+2, 1)
Q = int(input())
for _ in range(Q):
a, b, c = input().rstrip().split()
if a == "1":
b = int(b)
c = ord(c) - 97
t = A[b-1]
addbit(t, b+1, -1)
addbit(c, b+1, 1)
A[b-1] = c
else:
b, c = int(b), int(c)
s = 0
for t in range(26):
s += 1 if getsum(t, c+1) - getsum(t, b) else 0
print(s)
``` | output | 1 | 51,079 | 0 | 102,159 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,080 | 0 | 102,160 |
"Correct Solution:
```
def main():
import sys
input=sys.stdin.buffer.readline
n=int(input())+1
data=[[0]*n*2for _ in range(26)]
def update(i,x):
i+=n
for d in data:
j=i
if d[j]:
d[j]=0
j//=2
while j:
d[j]=d[j+j]|d[j-~j]
j//=2
break
d=data[x]
d[i]=1
i//=2
while i:
d[i]=d[i+i]|d[i-~i]
i//=2
def query(l,r):
l+=n
r+=n
s=[0]*26
while l<r:
if l&1:
for i,d in enumerate(data):
s[i]|=d[l]
l+=1
if r&1:
r-=1
for i,d in enumerate(data):
s[i]|=d[r]
l//=2
r//=2
return sum(s)
for i,c in enumerate(input()[:-1],n):
data[c-97][i]=1
for d in data:
for i in range(n-1,0,-1):
d[i]=d[i+i]|d[i-~i]
s=[]
for _ in range(int(input())):
q,a,b=input().split()
if q[0]>49:
s+=query(int(a)-1,int(b)),
else:
update(int(a)-1,b[0]-97)
print(' '.join(map(str,s)))
main()
``` | output | 1 | 51,080 | 0 | 102,161 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,081 | 0 | 102,162 |
"Correct Solution:
```
import sys
read=sys.stdin.readline
class SEGTree:
def __init__(self,n):
self.Unit=0
i=1
while(i<n):
i*=2
self.SEG=[self.Unit]*(2*i-1)
self.d=i
def update(self,i,x):
i+=self.d-1
self.SEG[i]=1<<x
while i>0:
i=(i-1)//2
self.SEG[i]=self.SEG[i*2+1]|self.SEG[i*2+2]
def find(self,a,b,k,l,r):
if r<=a or b<=l:
return self.Unit
if a<=l and r<=b:
return self.SEG[k]
else:
c1=self.find(a,b,2*k+1,l,(l+r)//2)
c2=self.find(a,b,2*k+2,(l+r)//2,r)
return c1|c2
def get(self,a,b):
return self.find(a,b,0,0,self.d)
def bitcnt(x):
res=0
while x>0:
if x&1:
res+=1
x//=2
return res
n=int(input())
s=input()
q=int(input())
seg=SEGTree(n)
for i in range(n):
seg.update(i,ord(s[i])-97)
for i in range(q):
q,x,y=read().rstrip().split()
if q=='1':
seg.update(int(x)-1,ord(y)-97)
else:
x,y=int(x)-1,int(y)
bit=seg.get(x,y)
print(bitcnt(bit))
``` | output | 1 | 51,081 | 0 | 102,163 |
Provide a correct Python 3 solution for this coding contest problem.
You are given a string S of length N consisting of lowercase English letters.
Process Q queries of the following two types:
* Type 1: change the i_q-th character of S to c_q. (Do nothing if the i_q-th character is already c_q.)
* Type 2: answer the number of different characters occurring in the substring of S between the l_q-th and r_q-th characters (inclusive).
Constraints
* N, Q, i_q, l_q, and r_q are integers.
* S is a string consisting of lowercase English letters.
* c_q is a lowercase English letter.
* 1 \leq N \leq 500000
* 1 \leq Q \leq 20000
* |S| = N
* 1 \leq i_q \leq N
* 1 \leq l_q \leq r_q \leq N
* There is at least one query of type 2 in each testcase.
Input
Input is given from Standard Input in the following format:
N
S
Q
Query_1
\vdots
Query_Q
Here, Query_i in the 4-th through (Q+3)-th lines is one of the following:
1 i_q c_q
2 l_q r_q
Output
For each query of type 2, print a line containing the answer.
Example
Input
7
abcdbbd
6
2 3 6
1 5 z
2 1 1
1 4 a
1 7 d
2 1 7
Output
3
1
5 | instruction | 0 | 51,082 | 0 | 102,164 |
"Correct Solution:
```
from bisect import bisect_left,bisect_right,insort
n = int(input())
s = list("-" + str(input()))
lis = [[] for i in range(26)]
for i in range(1,n+1):
num = ord(s[i])-ord("a")
lis[num].append(i)
q = int(input())
for turn in range(q):
query = list(map(str,input().split()))
if query[0] == "1":
a = int(query[1])
if s[a] == query[2]:
continue
num = ord(s[a])-ord("a")
lis[num].pop(bisect_left(lis[num],a))
next = ord(query[2])-ord("a")
insort(lis[next],a)
s[a] = query[2]
else:
a,b = int(query[1]),int(query[2])
ans = 0
for alphabet in range(26):
if bisect_right(lis[alphabet],b)-bisect_left(lis[alphabet],a) >= 1:
ans += 1
print(ans)
``` | output | 1 | 51,082 | 0 | 102,165 |
Provide a correct Python 3 solution for this coding contest problem.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11 | instruction | 0 | 51,258 | 0 | 102,516 |
"Correct Solution:
```
import random
n,m = map(int,input().split())
s = input()
#s[i:j]のハッシュ値:(hash1[j]-hash1[i]*power1[j-i]%mod1)%mod1,(hash2[j]-hash2[i]*power2[j-i]%mod2)%mod2
#長さnの文字列s
base1 = 1007
mod1 = 10**9+7
base2 = 2009
mod2 = 10**9+9
modTank1 = [3000012541,3000012553,3000012563,3000012649,3000012683,3000012709]
mod1 = modTank1[random.randint(0,5)]
modTank2 = [3000014753,3000014783,3000014833,3000014839,3000014891,3000015433]
mod2 = modTank2[random.randint(0,5)]
hash1 = [0]*(n+1)
power1 = [1]*(n+1)
hash2 = [0]*(n+1)
power2 = [1]*(n+1)
for i,e in enumerate(s):
hash1[i+1] = (hash1[i]*base1 + ord(e))%mod1
power1[i+1] = (power1[i]*base1)%mod1
hash2[i+1] = (hash2[i]*base2 + ord(e))%mod2
power2[i+1] = (power2[i]*base2)%mod2
res = 0
tank1 = set()
L = 0
R = 1
for _ in range(m):
q = input()
if q == 'L++':
L += 1
elif q == 'L--':
L -= 1
elif q == 'R++':
R += 1
else:
R -= 1
hashData1 = ((hash1[R]-hash1[L]*power1[R-L]%mod1)%mod1)*(10**10) + (hash2[R]-hash2[L]*power2[R-L]%mod2)%mod2
if hashData1 in tank1:
res += 1
tank1.add(hashData1)
print(len(tank1))
``` | output | 1 | 51,258 | 0 | 102,517 |
Provide a correct Python 3 solution for this coding contest problem.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11 | instruction | 0 | 51,259 | 0 | 102,518 |
"Correct Solution:
```
def main():
n, m = map(int, input().split())
s = input()
mem = set()
base = ord("a") - 1
mod1 = 1000000007
mod2 = 2147483647
h1 = [0]
h2 = [0]
for c in s:
h1.append((h1[-1] * 27 + ord(c) - base) % mod1)
h2.append((h2[-1] * 27 + ord(c) - base) % mod2)
pow_mem1 = {0:1}
pow_mem2 = {0:1}
def my_pow1(x):
if x in pow_mem1:return pow_mem1[x]
pow_mem1[x] = my_pow1(x - 1) * 27 % mod1
return pow_mem1[x]
def my_pow2(x):
if x in pow_mem2:return pow_mem2[x]
pow_mem2[x] = my_pow2(x - 1) * 27 % mod2
return pow_mem2[x]
left = right = 1
for _ in range(m):
com = input()
if com == "L++":
left += 1
if com == "L--":
left -= 1
if com == "R++":
right += 1
if com == "R--":
right -= 1
x = (h1[right] - h1[left - 1] * my_pow1(right - left + 1)) % mod1
y = (h2[right] - h2[left - 1] * my_pow2(right - left + 1)) % mod2
mem.add((x, y))
print(len(mem))
main()
``` | output | 1 | 51,259 | 0 | 102,519 |
Provide a correct Python 3 solution for this coding contest problem.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11 | instruction | 0 | 51,260 | 0 | 102,520 |
"Correct Solution:
```
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools
sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**13
mod = 10**9+7
dd = [(-1,0),(0,1),(1,0),(0,-1)]
ddn = [(-1,0),(-1,1),(0,1),(1,1),(1,0),(1,-1),(0,-1),(-1,-1)]
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)
class ModInt():
def __init__(self, n):
self.n = n
def __add__(self, x):
x = ModInt.xn(x)
return ModInt((self.n+x) % mod)
def __sub__(self, x):
x = ModInt.xn(x)
return ModInt((self.n-x) % mod)
def __mul__(self, x):
x = ModInt.xn(x)
return ModInt((self.n*x) % mod)
def __truediv__(self, x):
x = ModInt.xn(x)
return ModInt(self.n * pow(x, mod-2, mod) % mod)
@classmethod
def xn(cls, x):
if isinstance(x, ModInt):
return x.n
return x
def __str__(self):
return str(self.n)
def M(n): return ModInt(n)
class RollingHash():
def __init__(self, s):
self.N = n = len(s)
a = [ord(c) for c in s]
self.A1 = a1 = [M(a[0])]
self.A2 = a2 = [M(a[0])]
for c in a[1:]:
a1.append(a1[-1] * 997 + c)
a2.append(a2[-1] * 991 + c)
def get(self, l, r):
if l == 0:
return (self.A1[r].n, self.A2[r].n)
t1 = (self.A1[r] - self.A1[l-1] * pow(997, r-l+1, mod)).n
t2 = (self.A2[r] - self.A2[l-1] * pow(991, r-l+1, mod)).n
return (t1, t2)
def main():
rr = []
def f(n,m):
rs = set()
s = S()
qa = [S() for _ in range(m)]
l = 0
r = 0
rh = RollingHash(s)
for q in qa:
if q == 'L++':
l += 1
elif q == 'L--':
l -= 1
elif q == 'R++':
r += 1
else:
r -= 1
rs.add((l,r))
rrs = set()
for l, r in rs:
rrs.add(rh.get(l,r))
return len(rrs)
while 1:
n,m = LI()
if n == 0:
break
rr.append(f(n,m))
# print('rr', rr[-1])
break
return '\n'.join(map(str,rr))
print(main())
``` | output | 1 | 51,260 | 0 | 102,521 |
Provide a correct Python 3 solution for this coding contest problem.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11 | instruction | 0 | 51,261 | 0 | 102,522 |
"Correct Solution:
```
# coding:utf-8
INF = float('inf')
MOD = 10 ** 9 + 7
def inpl(): return list(map(int, input().split()))
class RollingHash:
def __init__(self, s, base, mod):
self.s = s
self.length = length = len(s)
self.base = base
self.mod = mod
self.h = h = [0] * (length + 1)
for i in range(length):
h[i + 1] = (h[i] * base + ord(s[i])) % mod
self.p = p = [1] * (length + 1)
for i in range(length):
p[i + 1] = pow(base, i + 1, mod)
def get(self, l, r):
mod = self.mod
# return (self.h[r] - self.h[l] * pow(self.base, r - l, mod) + mod) % mod
return ((self.h[r] - self.h[l] * self.p[r - l]) + mod) % mod
def solve():
N, M = inpl()
S = input()
h1 = RollingHash(S, 13, MOD)
h2 = RollingHash(S, 17, MOD)
left, right = 0, 1
vs = set()
ans = 0
for i in range(M):
q = input()
if q == 'R++':
right += 1
elif q == 'R--':
right -= 1
elif q == 'L++':
left += 1
else:
left -= 1
v = (h1.get(left, right), h2.get(left, right))
if v not in vs:
ans += 1
vs.add(v)
return ans
print(solve())
``` | output | 1 | 51,261 | 0 | 102,523 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11
Submitted Solution:
```
def main():
n, m = map(int, input().split())
s = input()
left = right = 0
mem = set()
for _ in range(m):
com = input()
if com == "L++":
left += 1
elif com == "L--":
left -= 1
elif com == "R++":
right += 1
elif com == "R--":
right -= 1
mem.add(s[left:right + 1])
print(len(mem))
main()
``` | instruction | 0 | 51,262 | 0 | 102,524 |
No | output | 1 | 51,262 | 0 | 102,525 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11
Submitted Solution:
```
n, m = map(int, input().split())
s = input()
left = right = 0
base = ord("a") - 1
score = ord(s[0]) - base
mem = set()
for _ in range(m):
com = input()
if com == "L++":
score //= 27
left += 1
elif com == "L--":
left -= 1
score = score * 27 + ord(s[left]) - base
elif com == "R++":
right += 1
score += 27 ** (right - left) * (ord(s[right]) - base)
elif com == "R--":
score -= 27 ** (right - left) * (ord(s[right]) - base)
right -= 1
if score not in mem:mem.add(score)
print(len(mem))
``` | instruction | 0 | 51,263 | 0 | 102,526 |
No | output | 1 | 51,263 | 0 | 102,527 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string of length n s = s1, s2,…, sn and m queries. Each query qk (1 ≤ k ≤ m) is one of four types, "L ++", "L-", "R ++", "R-", and l [for the kth query qk. k] and r [k] are defined below.
* L ++: l [k] = l [k-1] + 1, r [k] = r [k-1]
* L-: l [k] = l [k-1] -1, r [k] = r [k-1]
* R ++: l [k] = l [k-1], r [k] = r [k-1] +1
* R-: l [k] = l [k-1], r [k] = r [k-1] -1
However, l [0] = r [0] = 1.
At this time, how many kinds of character strings are created for m substrings sl [k], sl [k] + 1,…, sr [k] -1, sr [k] (1 ≤ k ≤ m). Answer if you can.
Constraints
* The string s consists of a lowercase alphabet
* 1 ≤ n ≤ 3 x 105
* 1 ≤ m ≤ 3 × 105
* qk (1 ≤ k ≤ m) is one of "L ++", "L-", "R ++", "R-"
* 1 ≤ l [k] ≤ r [k] ≤ n (1 ≤ k ≤ m)
Input
Input is given in the following format
> n m
> s
> q1
> q2
>…
> qm
>
Output
Output the solution of the problem on one line
Examples
Input
5 4
abcde
R++
R++
L++
L--
Output
3
Input
4 6
abab
R++
L++
R++
L++
R++
L++
Output
4
Input
10 13
aacacbabac
R++
R++
L++
R++
R++
L++
L++
R++
R++
L--
L--
R--
R--
Output
11
Submitted Solution:
```
def main():
n, m = map(int, input().split())
s = input()
mem = set()
base = ord("a") - 1
mod1 = 1000000007
mod2 = 2147483647
left = right = 0
score1 = score2 = ord(s[0]) - base
pow_mem1 = {0:1}
pow_mem2 = {0:1}
def my_pow1(x):
if x in pow_mem1:return pow_mem1[x]
pow_mem1[x] = my_pow1(x - 1) * 27 % mod1
return pow_mem1[x]
def my_pow2(x):
if x in pow_mem2:return pow_mem2[x]
pow_mem2[x] = my_pow2(x - 1) * 27 % mod2
return pow_mem2[x]
for _ in range(m):
com = input()
if com == "L++":
left += 1
score1 = score1 // 27
score2 = score2 // 27
if com == "L--":
left -= 1
score1 = score1 * 27 + ord(s[left]) - base
score2 = score2 * 27 + ord(s[left]) - base
if com == "R++":
right += 1
score1 += my_pow1(right - left) * (ord(s[right]) - base)
score2 += my_pow2(right - left) * (ord(s[right]) - base)
if com == "R--":
score1 -= my_pow1(right - left) * (ord(s[right]) - base)
score2 -= my_pow2(right - left) * (ord(s[right]) - base)
right -= 1
score1 %= mod1
score2 %= mod2
if (score1, score2) not in mem:mem.add((score1, score2))
print(len(mem))
main()
``` | instruction | 0 | 51,264 | 0 | 102,528 |
No | output | 1 | 51,264 | 0 | 102,529 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,362 | 0 | 102,724 |
Tags: implementation, strings
Correct Solution:
```
s=input()
l=len(s)
cnt=s.count('a')
print(min(l,cnt*2-1))
``` | output | 1 | 51,362 | 0 | 102,725 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,363 | 0 | 102,726 |
Tags: implementation, strings
Correct Solution:
```
w = input()
l = len(w)
a = w.count('a')
x = l - a
if a-x > 0:
print(l)
else:
print(l + a - x - 1)
``` | output | 1 | 51,363 | 0 | 102,727 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,364 | 0 | 102,728 |
Tags: implementation, strings
Correct Solution:
```
s=input()
q=s.count("a")
print(min(2*q-1,len(s)))
``` | output | 1 | 51,364 | 0 | 102,729 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,365 | 0 | 102,730 |
Tags: implementation, strings
Correct Solution:
```
my_string = input()
number_of_a = my_string.count('a')
print(min(number_of_a + number_of_a-1, len(my_string)), end='')
``` | output | 1 | 51,365 | 0 | 102,731 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,366 | 0 | 102,732 |
Tags: implementation, strings
Correct Solution:
```
s=input()
x=len(s)
count=0
for i in s:
if i=="a":
count+=1
y=x//2
if count>y:
print(len(s))
elif count<=y:
while count<=y:
y-=1
print(count+y)
``` | output | 1 | 51,366 | 0 | 102,733 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,367 | 0 | 102,734 |
Tags: implementation, strings
Correct Solution:
```
def mp():
return map(int, input().split())
s = input()
n = len(s)
a = s.count('a')
x = max(0, n - a * 2 + 1)
print(n - x)
``` | output | 1 | 51,367 | 0 | 102,735 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,368 | 0 | 102,736 |
Tags: implementation, strings
Correct Solution:
```
# AC
import sys
class Main:
def __init__(self):
self.buff = None
self.index = 0
def next(self):
if self.buff is None or self.index == len(self.buff):
self.buff = sys.stdin.readline().split()
self.index = 0
val = self.buff[self.index]
self.index += 1
return val
def next_int(self):
return int(self.next())
def solve(self):
ss = self.next()
ca = ss.count('a')
print(min(len(ss), ca * 2 - 1))
if __name__ == '__main__':
Main().solve()
``` | output | 1 | 51,368 | 0 | 102,737 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters. | instruction | 0 | 51,369 | 0 | 102,738 |
Tags: implementation, strings
Correct Solution:
```
s = input()
a, other = 0, 0
for c in s:
if c == 'a':
a += 1
else:
other += 1
if a > other:
print(len(s))
else:
print(len(s) - (other - (a - 1)))
``` | output | 1 | 51,369 | 0 | 102,739 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
s=input()
n=len(s)
c=0
m=[]
p=s.count('a')
q=n-p
if(p>q):
print(n)
else:
print(p+(p-1))
``` | instruction | 0 | 51,370 | 0 | 102,740 |
Yes | output | 1 | 51,370 | 0 | 102,741 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
word = [char for char in input()]
word_dict = {i:word.count(i) for i in word}
i = 0
if word_dict['a']/len(word) > 0.5:
print(len(word))
else:
while word_dict['a']/(len(word)- i) <= 0.5:
i+=1
print(len(word)-i)
``` | instruction | 0 | 51,371 | 0 | 102,742 |
Yes | output | 1 | 51,371 | 0 | 102,743 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
s = input()
a = s.count('a'); nota = len(s) - a
print(a + nota*(nota<a) + (a-1)*(nota>=a))
``` | instruction | 0 | 51,372 | 0 | 102,744 |
Yes | output | 1 | 51,372 | 0 | 102,745 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
# ===============================================================================================
# importing some useful libraries.
from __future__ import division, print_function
from fractions import Fraction
import sys
import os
from io import BytesIO, IOBase
from itertools import *
import bisect
from heapq import *
from math import *
from copy import *
from collections import deque
from collections import Counter as counter # Counter(list) return a dict with {key: count}
from itertools import combinations as comb # if a = [1,2,3] then print(list(comb(a,2))) -----> [(1, 2), (1, 3), (2, 3)]
from itertools import permutations as permutate
from bisect import bisect_left as bl
# If the element is already present in the list,
# the left most position where element has to be inserted is returned.
from bisect import bisect_right as br
from bisect import bisect
# If the element is already present in the list,
# the right most position where element has to be inserted is returned
# ==============================================================================================
# fast I/O region
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")
def print(*args, **kwargs):
"""Prints the values to a stream, or to sys.stdout by default."""
sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
at_start = True
for x in args:
if not at_start:
file.write(sep)
file.write(str(x))
at_start = False
file.write(kwargs.pop("end", "\n"))
if kwargs.pop("flush", False):
file.flush()
if sys.version_info[0] < 3:
sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
# inp = lambda: sys.stdin.readline().rstrip("\r\n")
# ===============================================================================================
### START ITERATE RECURSION ###
from types import GeneratorType
def iterative(f, stack=[]):
def wrapped_func(*args, **kwargs):
if stack: return f(*args, **kwargs)
to = f(*args, **kwargs)
while True:
if type(to) is GeneratorType:
stack.append(to)
to = next(to)
continue
stack.pop()
if not stack: break
to = stack[-1].send(to)
return to
return wrapped_func
#### END ITERATE RECURSION ####
# ===============================================================================================
# some shortcuts
mod = 1000000007
def inp(): return sys.stdin.readline().rstrip("\r\n") # for fast input
def out(var): sys.stdout.write(str(var)) # for fast output, always take string
def lis(): return list(map(int, inp().split()))
def stringlis(): return list(map(str, inp().split()))
def sep(): return map(int, inp().split())
def strsep(): return map(str, inp().split())
def zerolist(n): return [0] * n
def nextline(): out("\n") # as stdout.write always print sring.
def testcase(t):
for p in range(t):
solve()
def printlist(a):
for p in range(0, len(a)):
out(str(a[p]) + ' ')
def solve():
s=inp()
k=s.count("a")
n=len(s)
print(k+min(n-k,(k-1)))
solve()
``` | instruction | 0 | 51,373 | 0 | 102,746 |
Yes | output | 1 | 51,373 | 0 | 102,747 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
s=input()
k=0
for i in range(len(s)):
if s[i]=='a':
k+=1
if k==len(s):
print(k)
else:
print(k+1)
``` | instruction | 0 | 51,374 | 0 | 102,748 |
No | output | 1 | 51,374 | 0 | 102,749 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
n = input()
if n.count('a') <= len(n) - n.count('a'):
print(len(n) - n.count('a') * 2)
else:
print(len(n))
``` | instruction | 0 | 51,375 | 0 | 102,750 |
No | output | 1 | 51,375 | 0 | 102,751 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
s = input()
n = s.count('a')
if len(s) == n:
print(n)
else:
print(n+1)
``` | instruction | 0 | 51,376 | 0 | 102,752 |
No | output | 1 | 51,376 | 0 | 102,753 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Alice has a string s. She really likes the letter "a". She calls a string good if strictly more than half of the characters in that string are "a"s. For example "aaabb", "axaa" are good strings, and "baca", "awwwa", "" (empty string) are not.
Alice can erase some characters from her string s. She would like to know what is the longest string remaining after erasing some characters (possibly zero) to get a good string. It is guaranteed that the string has at least one "a" in it, so the answer always exists.
Input
The first line contains a string s (1 ≤ |s| ≤ 50) consisting of lowercase English letters. It is guaranteed that there is at least one "a" in s.
Output
Print a single integer, the length of the longest good string that Alice can get after erasing some characters from s.
Examples
Input
xaxxxxa
Output
3
Input
aaabaa
Output
6
Note
In the first example, it's enough to erase any four of the "x"s. The answer is 3 since that is the maximum number of characters that can remain.
In the second example, we don't need to erase any characters.
Submitted Solution:
```
n=input()
i=0
for e in n:
if(e=="a"):
i+=1
if(len(n)/2>i):
print(i+1)
elif(len(n)/2==i):
print(len(n)-1)
else:
print(len(n))
``` | instruction | 0 | 51,377 | 0 | 102,754 |
No | output | 1 | 51,377 | 0 | 102,755 |
Provide tags and a correct Python 3 solution for this coding contest problem.
A telephone number is a sequence of exactly 11 digits, where the first digit is 8. For example, the sequence 80011223388 is a telephone number, but the sequences 70011223388 and 80000011223388 are not.
You are given a string s of length n, consisting of digits.
In one operation you can delete any character from string s. For example, it is possible to obtain strings 112, 111 or 121 from string 1121.
You need to determine whether there is such a sequence of operations (possibly empty), after which the string s becomes a telephone number.
Input
The first line contains one integer t (1 ≤ t ≤ 100) — the number of test cases.
The first line of each test case contains one integer n (1 ≤ n ≤ 100) — the length of string s.
The second line of each test case contains the string s (|s| = n) consisting of digits.
Output
For each test print one line.
If there is a sequence of operations, after which s becomes a telephone number, print YES.
Otherwise, print NO.
Example
Input
2
13
7818005553535
11
31415926535
Output
YES
NO
Note
In the first test case you need to delete the first and the third digits. Then the string 7818005553535 becomes 88005553535. | instruction | 0 | 51,378 | 0 | 102,756 |
Tags: brute force, greedy, strings
Correct Solution:
```
for _ in range(int(input())):
n = int(input())
s = input()
idx = -1
for i in range(n):
if s[i] == '8':
idx = i
break
if n - idx >= 11 and idx != -1:
print('YES')
else:
print('NO')
``` | output | 1 | 51,378 | 0 | 102,757 |
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