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 |
|---|---|---|---|---|---|
Provide a correct Python 3 solution for this coding contest problem.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1 | instruction | 0 | 79,016 | 0 | 158,032 |
"Correct Solution:
```
# 2019/09/11
s=list(input())
n=len(s)
if n<3:
print(*[1,2] if len(set(s))<2 else [-1,-1])
exit()
ans=(-1,-1)
for i in range(1,n-1):
if len(set(s[i]+s[i-1]+s[i+1]))<3:
ans=(i,i+2)
break
print(*ans)
``` | output | 1 | 79,016 | 0 | 158,033 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
s=input()
for i in range(len(s)):
if i>=1:
if s[i]==s[i-1]:
print(i, i+1)
exit()
if i>=2:
if s[i]==s[i-2]:
print(i-1, i+1)
exit()
print(-1, -1)
``` | instruction | 0 | 79,017 | 0 | 158,034 |
Yes | output | 1 | 79,017 | 0 | 158,035 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
S = input()
for c in range(0, ord('z') - ord('a')+1):
last_c = -1
for i,s in enumerate(S):
if ord(s) - ord('a') == c:
if last_c == -1:
last_c = i
continue
if i - last_c <= 2:
print(last_c+1,i+1)
exit()
last_c = i
print(-1,-1)
``` | instruction | 0 | 79,018 | 0 | 158,036 |
Yes | output | 1 | 79,018 | 0 | 158,037 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
s=input()
n=len(s)
e,p,r=exit,print,range
for i in r(n-1):
if s[i]==s[i+1]:e(p(i+1,i+2))
for i in r(n-2):
if s[i]==s[i+2]:e(p(i+1,i+3))
p(-1,-1)
``` | instruction | 0 | 79,019 | 0 | 158,038 |
Yes | output | 1 | 79,019 | 0 | 158,039 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
a=input()
flag = 0
for i in range(len(a)-1):
if flag == 0:
if a[i]==a[i+1]:
print("{0} {1}".format(i+1,i+2))
flag = 1
elif i+2!=len(a) and a[i]==a[i+2]:
print("{0} {1}".format(i+1,i+3))
flag = 1
if flag == 0:
print("-1 -1")
``` | instruction | 0 | 79,020 | 0 | 158,040 |
Yes | output | 1 | 79,020 | 0 | 158,041 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
import sys
import collections
def solve():
readline = sys.stdin.buffer.readline
mod = 10 ** 9 + 7
s = str(readline().rstrip().decode('utf-8'))
q = collections.deque(list(s[:2]))
for i in range(2, len(s)):
q.append(s[i])
c = collections.Counter(q)
if len(c) == 2:
print(i - 2 + 1, i + 1)
exit()
q.popleft()
print(-1, - 1)
if __name__ == '__main__':
solve()
``` | instruction | 0 | 79,021 | 0 | 158,042 |
No | output | 1 | 79,021 | 0 | 158,043 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
from functools import reduce
import math
def main():
# 文字列の2進数を数値にする
# '101' → '5'
# 文字列の頭に'0b'をつけてint()にわたす
# binary = int('0b'+'101',0)
# 2進数で立っているbitを数える
# 101(0x5) → 2
# cnt_bit = bin(5).count('1')
# N! を求める
# f = math.factorial(N)
# 切り捨て
# 4 // 3
# 切り上げ
#-(-4 // 3)
# 初期値用:十分大きい数(100億)
INF = float("inf")
# 1文字のみを読み込み
# 入力:2
# a = input().rstrip()
# 変数:a='2'
# スペース区切りで標準入力を配列として読み込み
# 入力:2 4 5 7
# a, b, c, d = (int(_) for _ in input().split())
# 変数:a=2 b=4 c=5 d =7
# 1文字ずつ標準入力を配列として読み込み
# 入力:2 4 5 7
# a = list(int(_) for _ in input().split())
# 変数:a = [2, 4, 5, 7]
# 1文字ずつ標準入力を配列として読み込み
# 入力:2457
# a = list(int(_) for _ in input())
# 変数:a = [2, 4, 5, 7]
s = list(_ for _ in input())
left = -1
right = -1
for i in range(len(s)-2):
if(s[i+1]==s[i]):
left = i+1
right = i+2
break
elif(s[i+2]==s[i]):
left = i+1
right = i+3
break
print(left,right)
if __name__ == '__main__':
main()
``` | instruction | 0 | 79,022 | 0 | 158,044 |
No | output | 1 | 79,022 | 0 | 158,045 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
import collections
s = input()
ls = len(s)
if ls <=2:
print(-1,-1)
for i in range(2,ls):
tmp = collections.Counter(s[i-2:i+1])
if len(tmp.keys())<=2:
print(i-1,i+1)
exit()
print(-1,-1)
``` | instruction | 0 | 79,023 | 0 | 158,046 |
No | output | 1 | 79,023 | 0 | 158,047 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both `voodoo` and `melee` are unbalanced, while neither `noon` nor `a` is.
You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.
Constraints
* 2 ≦ |s| ≦ 10^5
* s consists of lowercase letters.
Input
The input is given from Standard Input in the following format:
s
Output
If there exists no unbalanced substring of s, print `-1 -1`.
If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print `a b`. If there exists more than one such substring, any of them will be accepted.
Examples
Input
needed
Output
2 5
Input
atcoder
Output
-1 -1
Submitted Solution:
```
s = list(input())
n = len(s)
check = False
for i in range(n-2):
temp = s[i:i+3]
temp.sort()
if temp[1] == temp[0] or temp[1] == temp[2]:
check = True
print(i+1,i+1+2)
break
if check == False:
print('-1 -1')
``` | instruction | 0 | 79,024 | 0 | 158,048 |
No | output | 1 | 79,024 | 0 | 158,049 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a matrix of size n × n filled with lowercase English letters. You can change no more than k letters in this matrix.
Consider all paths from the upper left corner to the lower right corner that move from a cell to its neighboring cell to the right or down. Each path is associated with the string that is formed by all the letters in the cells the path visits. Thus, the length of each string is 2n - 1.
Find the lexicographically smallest string that can be associated with a path after changing letters in at most k cells of the matrix.
A string a is lexicographically smaller than a string b, if the first different letter in a and b is smaller in a.
Input
The first line contains two integers n and k (1 ≤ n ≤ 2000, 0 ≤ k ≤ n^2) — the size of the matrix and the number of letters you can change.
Each of the next n lines contains a string of n lowercase English letters denoting one row of the matrix.
Output
Output the lexicographically smallest string that can be associated with some valid path after changing no more than k letters in the matrix.
Examples
Input
4 2
abcd
bcde
bcad
bcde
Output
aaabcde
Input
5 3
bwwwz
hrhdh
sepsp
sqfaf
ajbvw
Output
aaaepfafw
Input
7 6
ypnxnnp
pnxonpm
nxanpou
xnnpmud
nhtdudu
npmuduh
pmutsnz
Output
aaaaaaadudsnz
Note
In the first sample test case it is possible to change letters 'b' in cells (2, 1) and (3, 1) to 'a', then the minimum path contains cells (1, 1), (2, 1), (3, 1), (4, 1), (4, 2), (4, 3), (4, 4). The first coordinate corresponds to the row and the second coordinate corresponds to the column.
Submitted Solution:
```
n, m = map(int, input().split())
ans= list()
l = ''
for i in range(n-1):
l = input()
ans.append(l[0])
line=input()
for i in range(len(line)):
ans.append(line[i])
for i in range(m):
ans[i] = 'a'
print(''.join(ans))
``` | instruction | 0 | 79,131 | 0 | 158,262 |
No | output | 1 | 79,131 | 0 | 158,263 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a matrix of size n × n filled with lowercase English letters. You can change no more than k letters in this matrix.
Consider all paths from the upper left corner to the lower right corner that move from a cell to its neighboring cell to the right or down. Each path is associated with the string that is formed by all the letters in the cells the path visits. Thus, the length of each string is 2n - 1.
Find the lexicographically smallest string that can be associated with a path after changing letters in at most k cells of the matrix.
A string a is lexicographically smaller than a string b, if the first different letter in a and b is smaller in a.
Input
The first line contains two integers n and k (1 ≤ n ≤ 2000, 0 ≤ k ≤ n^2) — the size of the matrix and the number of letters you can change.
Each of the next n lines contains a string of n lowercase English letters denoting one row of the matrix.
Output
Output the lexicographically smallest string that can be associated with some valid path after changing no more than k letters in the matrix.
Examples
Input
4 2
abcd
bcde
bcad
bcde
Output
aaabcde
Input
5 3
bwwwz
hrhdh
sepsp
sqfaf
ajbvw
Output
aaaepfafw
Input
7 6
ypnxnnp
pnxonpm
nxanpou
xnnpmud
nhtdudu
npmuduh
pmutsnz
Output
aaaaaaadudsnz
Note
In the first sample test case it is possible to change letters 'b' in cells (2, 1) and (3, 1) to 'a', then the minimum path contains cells (1, 1), (2, 1), (3, 1), (4, 1), (4, 2), (4, 3), (4, 4). The first coordinate corresponds to the row and the second coordinate corresponds to the column.
Submitted Solution:
```
n, m = list(map(int, input().split()))
table = [' '.join(input()).split() for j in range(n)]
F = [[''] * (n + 1) for i in range(n + 1)]
for i in range(2, n + 1):
F[i][0] = 'z'
for j in range(2, n + 1):
F[0][j] = 'z'
for i in range(1, n + 1):
for j in range(1, n + 1):
F[i][j] = min(F[i - 1][j], F[i][j - 1]) + table[i - 1][j - 1]
if m != 0:
for j in F[n][n]:
if m == 0:
print(j, end='')
else:
if j != 'a':
print('a', end='')
m -= 1
else:
print(j, end='')
``` | instruction | 0 | 79,132 | 0 | 158,264 |
No | output | 1 | 79,132 | 0 | 158,265 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a matrix of size n × n filled with lowercase English letters. You can change no more than k letters in this matrix.
Consider all paths from the upper left corner to the lower right corner that move from a cell to its neighboring cell to the right or down. Each path is associated with the string that is formed by all the letters in the cells the path visits. Thus, the length of each string is 2n - 1.
Find the lexicographically smallest string that can be associated with a path after changing letters in at most k cells of the matrix.
A string a is lexicographically smaller than a string b, if the first different letter in a and b is smaller in a.
Input
The first line contains two integers n and k (1 ≤ n ≤ 2000, 0 ≤ k ≤ n^2) — the size of the matrix and the number of letters you can change.
Each of the next n lines contains a string of n lowercase English letters denoting one row of the matrix.
Output
Output the lexicographically smallest string that can be associated with some valid path after changing no more than k letters in the matrix.
Examples
Input
4 2
abcd
bcde
bcad
bcde
Output
aaabcde
Input
5 3
bwwwz
hrhdh
sepsp
sqfaf
ajbvw
Output
aaaepfafw
Input
7 6
ypnxnnp
pnxonpm
nxanpou
xnnpmud
nhtdudu
npmuduh
pmutsnz
Output
aaaaaaadudsnz
Note
In the first sample test case it is possible to change letters 'b' in cells (2, 1) and (3, 1) to 'a', then the minimum path contains cells (1, 1), (2, 1), (3, 1), (4, 1), (4, 2), (4, 3), (4, 4). The first coordinate corresponds to the row and the second coordinate corresponds to the column.
Submitted Solution:
```
import os
import sys
from io import BytesIO, IOBase
# 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")
# ------------------------------
from types import GeneratorType
def bootstrap(f, stack=[]):
def wrappedfunc(*args, **kwargs):
if stack:
return f(*args, **kwargs)
else:
to = f(*args, **kwargs)
while True:
if type(to) is GeneratorType:
stack.append(to)
to = next(to)
else:
stack.pop()
if not stack:
break
to = stack[-1].send(to)
return to
return wrappedfunc
def RL(): return map(int, sys.stdin.readline().rstrip().split())
def RLL(): return list(map(int, sys.stdin.readline().rstrip().split()))
def N(): return int(input())
def comb(n, m): return factorial(n) / (factorial(m) * factorial(n - m)) if n >= m else 0
def perm(n, m): return factorial(n) // (factorial(n - m)) if n >= m else 0
def mdis(x1, y1, x2, y2): return abs(x1 - x2) + abs(y1 - y2)
mod = 998244353
INF = float('inf')
from math import factorial
from collections import Counter, defaultdict, deque
from heapq import heapify, heappop, heappush
# ------------------------------
# f = open('./input.txt')
# sys.stdin = f
def main():
n, k = RL()
arr = [input() for _ in range(n)]
dp = [[INF]*(n) for _ in range(n)]
q = deque()
pre = 0
for i in range(n):
for j in range(n):
if i==0 and j==0:
dp[0][0] = 1 if arr[0][0] != 'a' else 0
elif i==0: dp[0][j] = dp[0][j-1] + (1 if arr[0][j]!='a' else 0 )
elif j==0: dp[i][0] = dp[i-1][0] + (1 if arr[0][i]!='a' else 0)
else: dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + (1 if arr[i][j]!='a' else 0)
if dp[i][j]<=k:
pre = max(pre, i+j+1)
suf = 2*n-1-pre
res = ['a']*pre + ['z']*suf
vis = [[0]*n for _ in range(n)]
q = []
for i in range(n):
for j in range(n):
if dp[i][j]==k and i+j+1==pre:
if i+1<n and vis[i+1][j]==0: q.append((i+1, j)); vis[i+1][j] = 1
if j+1<n and vis[i][j+1]==0: q.append((i, j+1)); vis[i][j+1] = 1
q.sort(key=lambda a: arr[a[0]][a[1]])
if not q: q.append((0, 0))
for i in range(pre, len(res)):
newq = []
res[i] = arr[q[0][0]][q[0][1]]
for j in range(len(q)):
now = arr[q[j][0]][q[j][1]]
if now!=res[i]: break
for nx, ny in [[1, 0], [0, 1]]:
xx, yy = nx+q[j][0], ny+q[j][1]
if xx<n and yy<n and vis[xx][yy]==0:
vis[xx][yy] = 1
if newq and arr[xx][yy]<arr[newq[-1][0]][newq[-1][1]]:
newq = []
newq.append((xx, yy))
q = newq
print("".join(res))
if __name__ == "__main__":
main()
``` | instruction | 0 | 79,133 | 0 | 158,266 |
No | output | 1 | 79,133 | 0 | 158,267 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
You are given a matrix of size n × n filled with lowercase English letters. You can change no more than k letters in this matrix.
Consider all paths from the upper left corner to the lower right corner that move from a cell to its neighboring cell to the right or down. Each path is associated with the string that is formed by all the letters in the cells the path visits. Thus, the length of each string is 2n - 1.
Find the lexicographically smallest string that can be associated with a path after changing letters in at most k cells of the matrix.
A string a is lexicographically smaller than a string b, if the first different letter in a and b is smaller in a.
Input
The first line contains two integers n and k (1 ≤ n ≤ 2000, 0 ≤ k ≤ n^2) — the size of the matrix and the number of letters you can change.
Each of the next n lines contains a string of n lowercase English letters denoting one row of the matrix.
Output
Output the lexicographically smallest string that can be associated with some valid path after changing no more than k letters in the matrix.
Examples
Input
4 2
abcd
bcde
bcad
bcde
Output
aaabcde
Input
5 3
bwwwz
hrhdh
sepsp
sqfaf
ajbvw
Output
aaaepfafw
Input
7 6
ypnxnnp
pnxonpm
nxanpou
xnnpmud
nhtdudu
npmuduh
pmutsnz
Output
aaaaaaadudsnz
Note
In the first sample test case it is possible to change letters 'b' in cells (2, 1) and (3, 1) to 'a', then the minimum path contains cells (1, 1), (2, 1), (3, 1), (4, 1), (4, 2), (4, 3), (4, 4). The first coordinate corresponds to the row and the second coordinate corresponds to the column.
Submitted Solution:
```
n, k = map(int, input().split())
matrix = [input() for _ in range(n)]
if k >= 2 * n - 1:
print('a' * (2 * n - 1))
else:
prev = [0] * n
if matrix[0][0] != 'a':
if k > 0:
prev[0] = 1
else:
prev[0] = matrix[0][0]
for i in range(1, n):
if isinstance(prev[i - 1], int):
if matrix[0][i] == 'a':
prev[i] = prev[i - 1]
elif prev[i - 1] == k:
prev[i] = ('a' * i) + matrix[0][i]
else:
prev[i] = prev[i - 1] + 1
else:
prev[i] = prev[i - 1] + matrix[0][i]
for i in range(1, n):
next = [0] * n
if isinstance(prev[0], int):
if matrix[i][0] == 'a':
next[0] = prev[0]
elif prev[0] == k:
next[0] = ('a' * i) + matrix[i][0]
else:
next[0] = prev[0] + 1
else:
next[0] = prev[0] + matrix[i][0]
for j in range(1, n):
if isinstance(prev[j], int):
if isinstance(next[j - 1], int):
val = min(prev[j], next[j - 1])
if matrix[i][j] == 'a':
next[j] = val
elif val == k:
next[j] = ('a' * (i + j)) + matrix[i][j]
else:
next[j] = val + 1
else:
val = prev[j]
if matrix[i][j] == 'a':
next[j] = val
elif val == k:
next[j] = ('a' * (i + j)) + matrix[i][j]
else:
next[j] = val + 1
else:
if isinstance(next[j - 1], int):
val = next[j - 1]
if matrix[i][j] == 'a':
next[j] = val
elif val == k:
next[j] = ('a' * (i + j)) + matrix[i][j]
else:
next[j] = val + 1
else:
next[j] = min(prev[j], next[j - 1]) + matrix[i][j]
prev = next
print(prev[-1])
``` | instruction | 0 | 79,134 | 0 | 158,268 |
No | output | 1 | 79,134 | 0 | 158,269 |
Provide tags and a correct Python 3 solution for this coding contest problem.
This problem is different with hard version only by constraints on total answers length
It is an interactive problem
Venya joined a tour to the madhouse, in which orderlies play with patients the following game. Orderlies pick a string s of length n, consisting only of lowercase English letters. The player can ask two types of queries:
* ? l r – ask to list all substrings of s[l..r]. Substrings will be returned in random order, and in every substring, all characters will be randomly shuffled.
* ! s – guess the string picked by the orderlies. This query can be asked exactly once, after that the game will finish. If the string is guessed correctly, the player wins, otherwise he loses.
The player can ask no more than 3 queries of the first type.
To make it easier for the orderlies, there is an additional limitation: the total number of returned substrings in all queries of the first type must not exceed (n+1)^2.
Venya asked you to write a program, which will guess the string by interacting with the orderlies' program and acting by the game's rules.
Your program should immediately terminate after guessing the string using a query of the second type. In case your program guessed the string incorrectly, or it violated the game rules, it will receive verdict Wrong answer.
Note that in every test case the string is fixed beforehand and will not change during the game, which means that the interactor is not adaptive.
Input
First line contains number n (1 ≤ n ≤ 100) — the length of the picked string.
Interaction
You start the interaction by reading the number n.
To ask a query about a substring from l to r inclusively (1 ≤ l ≤ r ≤ n), you should output
? l r
on a separate line. After this, all substrings of s[l..r] will be returned in random order, each substring exactly once. In every returned substring all characters will be randomly shuffled.
In the case, if you ask an incorrect query, ask more than 3 queries of the first type or there will be more than (n+1)^2 substrings returned in total, you will receive verdict Wrong answer.
To guess the string s, you should output
! s
on a separate line.
After printing each query, do not forget to flush the output. Otherwise, you will get Idleness limit exceeded. To flush the output, you can use:
* fflush(stdout) or cout.flush() in C++;
* System.out.flush() in Java;
* flush(output) in Pascal;
* stdout.flush() in Python;
* see documentation for other languages.
If you received - (dash) as an answer to any query, you need to terminate your program with exit code 0 (for example, by calling exit(0)). This means that there was an error in the interaction protocol. If you don't terminate with exit code 0, you can receive any unsuccessful verdict.
Hack format
To hack a solution, use the following format:
The first line should contain one integer n (1 ≤ n ≤ 100) — the length of the string, and the following line should contain the string s.
Example
Input
4
a
aa
a
cb
b
c
c
Output
? 1 2
? 3 4
? 4 4
! aabc | instruction | 0 | 79,283 | 0 | 158,566 |
Tags: brute force, constructive algorithms, interactive, math
Correct Solution:
```
mod = 1000000007
eps = 10**-9
def main():
import sys
from collections import Counter
input = sys.stdin.readline
def ask(l, r):
print(*["?", l, r])
sys.stdout.flush()
N = int(input())
ask(1, N)
ret1 = []
for _ in range(N * (N+1) // 2):
s = input().rstrip('\n')
if s == "-":
exit()
ret1.append("".join(sorted(s)))
if N == 1:
ans = ret1[0]
print("!", ans)
sys.stdout.flush()
exit()
ask(1, N-1)
ret2 = []
for _ in range(N * (N - 1) // 2):
s = input().rstrip('\n')
if s == "-":
exit()
ret2.append("".join(sorted(s)))
dic1 = [{} for _ in range(N+1)]
dic2 = [{} for _ in range(N+1)]
for s in ret1:
L = len(s)
if L == N:
S_all = s
if s in dic1[L]:
dic1[L][s] += 1
else:
dic1[L][s] = 1
for s in ret2:
L = len(s)
if s in dic2[L]:
dic2[L][s] += 1
else:
dic2[L][s] = 1
right = [""] * (N+1)
for L in range(N-1, 0, -1):
for s in dic1[L]:
if s not in dic2[L]:
right[L] = s
break
if dic1[L][s] != dic2[L][s]:
right[L] = s
break
ans = [""] * N
dic = {chr(i+97): 0 for i in range(26)}
for L in range(1, N):
C = Counter(right[L])
for i in range(26):
s = chr(i+97)
if dic[s] != C[s]:
ans[-L] = s
dic[s] += 1
break
#print(ans, L, right[L])
C = Counter(S_all)
for i in range(26):
s = chr(i + 97)
if dic[s] != C[s]:
ans[0] = s
dic[s] += 1
break
print("!", "".join(ans))
sys.stdout.flush()
if __name__ == '__main__':
main()
``` | output | 1 | 79,283 | 0 | 158,567 |
Provide tags and a correct Python 3 solution for this coding contest problem.
This problem is different with hard version only by constraints on total answers length
It is an interactive problem
Venya joined a tour to the madhouse, in which orderlies play with patients the following game. Orderlies pick a string s of length n, consisting only of lowercase English letters. The player can ask two types of queries:
* ? l r – ask to list all substrings of s[l..r]. Substrings will be returned in random order, and in every substring, all characters will be randomly shuffled.
* ! s – guess the string picked by the orderlies. This query can be asked exactly once, after that the game will finish. If the string is guessed correctly, the player wins, otherwise he loses.
The player can ask no more than 3 queries of the first type.
To make it easier for the orderlies, there is an additional limitation: the total number of returned substrings in all queries of the first type must not exceed (n+1)^2.
Venya asked you to write a program, which will guess the string by interacting with the orderlies' program and acting by the game's rules.
Your program should immediately terminate after guessing the string using a query of the second type. In case your program guessed the string incorrectly, or it violated the game rules, it will receive verdict Wrong answer.
Note that in every test case the string is fixed beforehand and will not change during the game, which means that the interactor is not adaptive.
Input
First line contains number n (1 ≤ n ≤ 100) — the length of the picked string.
Interaction
You start the interaction by reading the number n.
To ask a query about a substring from l to r inclusively (1 ≤ l ≤ r ≤ n), you should output
? l r
on a separate line. After this, all substrings of s[l..r] will be returned in random order, each substring exactly once. In every returned substring all characters will be randomly shuffled.
In the case, if you ask an incorrect query, ask more than 3 queries of the first type or there will be more than (n+1)^2 substrings returned in total, you will receive verdict Wrong answer.
To guess the string s, you should output
! s
on a separate line.
After printing each query, do not forget to flush the output. Otherwise, you will get Idleness limit exceeded. To flush the output, you can use:
* fflush(stdout) or cout.flush() in C++;
* System.out.flush() in Java;
* flush(output) in Pascal;
* stdout.flush() in Python;
* see documentation for other languages.
If you received - (dash) as an answer to any query, you need to terminate your program with exit code 0 (for example, by calling exit(0)). This means that there was an error in the interaction protocol. If you don't terminate with exit code 0, you can receive any unsuccessful verdict.
Hack format
To hack a solution, use the following format:
The first line should contain one integer n (1 ≤ n ≤ 100) — the length of the string, and the following line should contain the string s.
Example
Input
4
a
aa
a
cb
b
c
c
Output
? 1 2
? 3 4
? 4 4
! aabc | instruction | 0 | 79,284 | 0 | 158,568 |
Tags: brute force, constructive algorithms, interactive, math
Correct Solution:
```
from bisect import bisect_left as bl
from bisect import bisect_right as br
import heapq
import math
from collections import *
from functools import reduce,cmp_to_key
import sys
input = sys.stdin.readline
# M = mod = 998244353
def factors(n):return sorted(list(set(reduce(list.__add__,([i, n//i] for i in range(1, int(n**0.5) + 1) if n % i == 0)))))
# def inv_mod(n):return pow(n, mod - 2, mod)
def li():return [int(i) for i in input().rstrip('\n').split(' ')]
def st():return input().rstrip('\n')
def val():return int(input().rstrip('\n'))
def li2():return [i for i in input().rstrip('\n').split(' ')]
def li3():return [int(i) for i in input().rstrip('\n')]
n = val()
cnt1 = Counter()
cnt2 = Counter()
print('? 1 ' + str(n),flush = True)
le = 0
for i in range(n):
for j in range(i+1,n+1):le += 1
for j in range(le):
cnt1[''.join(sorted(st()))] += 1
if n == 1:
for i in cnt1.keys():
print('! ' + str(i),flush = True)
exit()
print('? 2 ' + str(n),flush = True)
le = 0
for i in range(1,n):
for j in range(i+1,n+1):le += 1
# print(le)
for i in range(le):
cnt2[''.join(sorted(st()))] += 1
cnt1 -= cnt2
cnt1 = sorted(list(cnt1),key = lambda x:len(x))
s = ''
currcount = Counter()
for i in cnt1:
currcount = Counter(s)
for j in i:
if not currcount[j]:
s += j
break
currcount[j] -= 1
print('! ' + s,flush = True)
``` | output | 1 | 79,284 | 0 | 158,569 |
Provide tags and a correct Python 3 solution for this coding contest problem.
This problem is different with hard version only by constraints on total answers length
It is an interactive problem
Venya joined a tour to the madhouse, in which orderlies play with patients the following game. Orderlies pick a string s of length n, consisting only of lowercase English letters. The player can ask two types of queries:
* ? l r – ask to list all substrings of s[l..r]. Substrings will be returned in random order, and in every substring, all characters will be randomly shuffled.
* ! s – guess the string picked by the orderlies. This query can be asked exactly once, after that the game will finish. If the string is guessed correctly, the player wins, otherwise he loses.
The player can ask no more than 3 queries of the first type.
To make it easier for the orderlies, there is an additional limitation: the total number of returned substrings in all queries of the first type must not exceed (n+1)^2.
Venya asked you to write a program, which will guess the string by interacting with the orderlies' program and acting by the game's rules.
Your program should immediately terminate after guessing the string using a query of the second type. In case your program guessed the string incorrectly, or it violated the game rules, it will receive verdict Wrong answer.
Note that in every test case the string is fixed beforehand and will not change during the game, which means that the interactor is not adaptive.
Input
First line contains number n (1 ≤ n ≤ 100) — the length of the picked string.
Interaction
You start the interaction by reading the number n.
To ask a query about a substring from l to r inclusively (1 ≤ l ≤ r ≤ n), you should output
? l r
on a separate line. After this, all substrings of s[l..r] will be returned in random order, each substring exactly once. In every returned substring all characters will be randomly shuffled.
In the case, if you ask an incorrect query, ask more than 3 queries of the first type or there will be more than (n+1)^2 substrings returned in total, you will receive verdict Wrong answer.
To guess the string s, you should output
! s
on a separate line.
After printing each query, do not forget to flush the output. Otherwise, you will get Idleness limit exceeded. To flush the output, you can use:
* fflush(stdout) or cout.flush() in C++;
* System.out.flush() in Java;
* flush(output) in Pascal;
* stdout.flush() in Python;
* see documentation for other languages.
If you received - (dash) as an answer to any query, you need to terminate your program with exit code 0 (for example, by calling exit(0)). This means that there was an error in the interaction protocol. If you don't terminate with exit code 0, you can receive any unsuccessful verdict.
Hack format
To hack a solution, use the following format:
The first line should contain one integer n (1 ≤ n ≤ 100) — the length of the string, and the following line should contain the string s.
Example
Input
4
a
aa
a
cb
b
c
c
Output
? 1 2
? 3 4
? 4 4
! aabc | instruction | 0 | 79,285 | 0 | 158,570 |
Tags: brute force, constructive algorithms, interactive, math
Correct Solution:
```
import sys
input = sys.stdin.readline
from bisect import bisect_left
n = int(input())
print('?', 1, n)
sys.stdout.flush()
m = (n + 1) // 2
l1 = [[0] * 26 for _ in range(m + 1)]
for i in range(n * (n + 1) // 2):
s = input()[:-1]
if len(s) <= m:
for j in range(len(s)):
l1[len(s)][ord(s[j]) - 97] += 1
for i in range(m, 0, -1):
for j in range(26):
l1[i][j] -= l1[i - 1][j]
for i in range(m):
for j in range(26):
l1[i][j] -= l1[i + 1][j]
if n > 1:
n = n - 1
print('?', 1, n)
sys.stdout.flush()
m = (n + 1) // 2
l2 = [[0] * 26 for _ in range(m + 1)]
for i in range(n * (n + 1) // 2):
s = input()[:-1]
if len(s) <= m:
for j in range(len(s)):
l2[len(s)][ord(s[j]) - 97] += 1
for i in range(m, 0, -1):
for j in range(26):
l2[i][j] -= l2[i - 1][j]
for i in range(m):
for j in range(26):
l2[i][j] -= l2[i + 1][j]
n += 1
x = [-1] * n
y = [-1] * n
for i in range(n):
if i % 2 == 0:
for j in range(26):
if l1[i//2+1][j] >= 1:
l1[i//2+1][j] -= 1
x[i] = j
break
for j in range(26):
if l1[i//2+1][j] >= 1:
l1[i//2+1][j] -= 1
y[i] = j
break
else:
for j in range(26):
if l2[i//2+1][j] >= 1:
l2[i//2+1][j] -= 1
x[i] = j
break
for j in range(26):
if l2[i//2+1][j] >= 1:
l2[i//2+1][j] -= 1
y[i] = j
break
ans = [0] * n
m = (n + 1) // 2
ll = []
if n % 2 == 1:
ll.append(n // 2)
for i in range(n // 2):
ll.append(n // 2 - i - 1)
ll.append(n // 2 + i + 1)
else:
for i in range(n // 2):
ll.append(n // 2 - i - 1)
ll.append(n // 2 + i)
ans[ll[0]] = x[-1]
t = 0
for i in range(n - 1):
if t == 0:
if x[n - i - 2] == x[n - i - 1]:
ans[ll[i + 1]] = y[n - i - 2]
t = 1
else:
ans[ll[i + 1]] = x[n - i - 2]
else:
if x[n - i - 2] == y[n - i - 1]:
ans[ll[i + 1]] = y[n - i - 2]
else:
ans[ll[i + 1]] = x[n - i - 2]
t = 0
print('! ', *map(lambda x:chr(x+97), ans), sep='')
``` | output | 1 | 79,285 | 0 | 158,571 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s of 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation. | instruction | 0 | 79,350 | 0 | 158,700 |
Tags: data structures, graphs, greedy
Correct Solution:
```
import io,os, sys
input = sys.stdin.readline
print = sys.stdout.write
t = int(input())
START = 500001
seen = [0] * (2 * START)
while t > 0:
t -= 1
s = input().strip("\n")
cur = START
for c in s:
if c == '0':
seen[cur] += 1
cur -= 1
else:
cur += 1
seen[cur] += 1
cur = START
while True:
if seen[cur] > 1 or seen[cur] > 0 and seen[cur + 1] == 0:
seen[cur] -= 1
cur -= 1
print('0')
elif seen[cur + 1] > 0:
cur += 1
seen[cur] -= 1
print('1')
else:
break
print("\n")
``` | output | 1 | 79,350 | 0 | 158,701 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s of 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation. | instruction | 0 | 79,351 | 0 | 158,702 |
Tags: data structures, graphs, greedy
Correct Solution:
```
# test Arpa code
import io,os, sys
input = sys.stdin.readline
print = sys.stdout.write
t = int(input())
START = 500001
seen = [0] * (2 * START)
while t > 0:
t -= 1
s = input().strip("\n")
cur = START
for c in s:
if c == '0':
seen[cur] += 1
cur -= 1
else:
cur += 1
seen[cur] += 1
cur = START
while True:
if seen[cur] > 1 or seen[cur] > 0 and seen[cur + 1] == 0:
seen[cur] -= 1
cur -= 1
print('0')
elif seen[cur + 1] > 0:
cur += 1
seen[cur] -= 1
print('1')
else:
break
print("\n")
``` | output | 1 | 79,351 | 0 | 158,703 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string s of 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation. | instruction | 0 | 79,352 | 0 | 158,704 |
Tags: data structures, graphs, greedy
Correct Solution:
```
import os
import sys
from io import BytesIO, IOBase
def main():
pass
# 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")
t = int(input())
START = 500001
seen = [0] * (2 * START)
while t > 0:
t -= 1
s = input()
cur = START
for c in s:
if c == '0':
seen[cur] += 1
cur -= 1
else:
cur += 1
seen[cur] += 1
cur = START
while True:
if seen[cur] > 1 or seen[cur] > 0 and seen[cur + 1] == 0:
seen[cur] -= 1
cur -= 1
print('0', end='', flush=False)
elif seen[cur + 1] > 0:
cur += 1
seen[cur] -= 1
print('1', end='', flush=False)
else:
break
print(flush=False)
``` | output | 1 | 79,352 | 0 | 158,705 |
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 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation.
Submitted Solution:
```
import sys
input = sys.stdin.readline
t = int(input())
out = []
for _ in range(t):
s = input().strip()
oc = 0
ec = 0
su = 0
n = len(s)
for i in range(n):
if s[i] == '1':
su += i
if i % 2:
oc += 1
else:
ec += 1
while n:
p1 = (n + 1)//2 == ec
p2 = (oc * oc + ec * ec + ec) > su
if p1 or p2:
out.append('1')
ec -= 1
else:
out.append('0')
su -= (oc + ec)
oc,ec = ec,oc
n -= 1
out.append('\n')
print(''.join(out))
``` | instruction | 0 | 79,353 | 0 | 158,706 |
No | output | 1 | 79,353 | 0 | 158,707 |
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 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation.
Submitted Solution:
```
t = int(input())
while t > 0:
t -= 1
s = input()
start = len(s) + 2
seen = [0] * (2 * len(s) + 4)
cur = start
for c in s:
if c == '0':
seen[cur] += 1
cur -= 1
else:
cur += 1
seen[cur] += 1
cur = start
while True:
if seen[cur] > 0:
seen[cur] -= 1
cur -= 1
print('0', end='')
elif seen[cur + 1] > 0:
cur += 1
seen[cur] -= 1
print('1', end='')
else:
break
print()
``` | instruction | 0 | 79,354 | 0 | 158,708 |
No | output | 1 | 79,354 | 0 | 158,709 |
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 0's and 1's. You are allowed to perform the following operation:
* choose a non-empty contiguous substring of s that contains an equal number of 0's and 1's;
* flip all characters in the substring, that is, replace all 0's with 1's, and vice versa;
* reverse the substring.
For example, consider s = 00111011, and the following operation:
* Choose the first six characters as the substring to act upon: 00111011. Note that the number of 0's and 1's are equal, so this is a legal choice. Choosing substrings 0, 110, or the entire string would not be possible.
* Flip all characters in the substring: 11000111.
* Reverse the substring: 10001111.
Find the lexicographically smallest string that can be obtained from s after zero or more operations.
Input
The first line contains a single integer T (1 ≤ T ≤ 5 ⋅ 10^5) — the number of test cases. Each of the following T lines contains a single non-empty string — the input string s for the respective test case.
All strings consist of characters 0 and 1, and their total length does not exceed 5 ⋅ 10^5.
Output
For each test case, on a separate line print the lexicographically smallest string that can be obtained from s after zero or more operations.
Example
Input
3
100101
1100011
10101010
Output
010110
0110110
10101010
Note
In the first test case a single operation should be applied to the entire string.
In the second test case two operations are needed: 0111001, 0110110.
In the third test case the string stays the same after any operation.
Submitted Solution:
```
import sys
input = sys.stdin.readline
t = int(input())
out = []
for _ in range(t):
s = input()
oc = 0
ec = 0
su = 0
n = len(s)
for i in range(n):
if s[i] == '1':
su += i
if i % 2:
oc += 1
else:
ec += 1
while n:
p1 = (n + 1)//2 == ec
p2 = (oc * oc + ec * ec + ec) > su
if p1 or p2:
out.append('1')
ec -= 1
else:
out.append('0')
su -= (oc + ec)
oc,ec = ec,oc
n -= 1
out.append('\n')
print(''.join(out))
``` | instruction | 0 | 79,355 | 0 | 158,710 |
No | output | 1 | 79,355 | 0 | 158,711 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,649 | 0 | 159,298 |
Tags: constructive algorithms
Correct Solution:
```
s = list(input())
k = s.copy()
k.reverse()
if s == k:
print(''.join(s))
else:
k = s[:len(s)-1]
k.reverse()
s.extend(k)
print(''.join(s))
``` | output | 1 | 79,649 | 0 | 159,299 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,650 | 0 | 159,300 |
Tags: constructive algorithms
Correct Solution:
```
'''n,m = map(int,input().split())
l = list(map(int,input().split()))
k = list(map(int,input().split()))
ans = 0
while len(l) != 0:
if len(l) >= len(k:
if l[0] <= k[0]:
ans += 1
del(l[0])
del(k[0])
else:
del(l[0])
else:
print(ans)
exit()
print(ans)
'''
s = list(input())
for i in s:
print(i,end="")
s.reverse()
for i in s:
print(i,end="")
``` | output | 1 | 79,650 | 0 | 159,301 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,651 | 0 | 159,302 |
Tags: constructive algorithms
Correct Solution:
```
import copy
a = list(input())
b = copy.copy(a)
b.reverse()
print("".join(str(i) for i in a + b))
``` | output | 1 | 79,651 | 0 | 159,303 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,652 | 0 | 159,304 |
Tags: constructive algorithms
Correct Solution:
```
s=input()
l=list(s)
l.reverse()
s1=''.join(l)
print(s+s1)
``` | output | 1 | 79,652 | 0 | 159,305 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,653 | 0 | 159,306 |
Tags: constructive algorithms
Correct Solution:
```
s = input()
print(s + ''.join(s[-i - 1] for i in range(len(s))))
``` | output | 1 | 79,653 | 0 | 159,307 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,654 | 0 | 159,308 |
Tags: constructive algorithms
Correct Solution:
```
line = input()
len1 = len(line)
string = line[::-1]
print(line+string)
``` | output | 1 | 79,654 | 0 | 159,309 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,655 | 0 | 159,310 |
Tags: constructive algorithms
Correct Solution:
```
import sys
if sys.version_info < (3, 0):
lrange = range
input = raw_input
range = xrange
s = input()
print(s+s[::-1])
``` | output | 1 | 79,655 | 0 | 159,311 |
Provide tags and a correct Python 3 solution for this coding contest problem.
You are given a string A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome. | instruction | 0 | 79,656 | 0 | 159,312 |
Tags: constructive algorithms
Correct Solution:
```
inp = input()
print(inp+inp[::-1])
``` | output | 1 | 79,656 | 0 | 159,313 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
def superpalindrom(s):
return s + s[::-1]
print(superpalindrom(input()))
``` | instruction | 0 | 79,657 | 0 | 159,314 |
Yes | output | 1 | 79,657 | 0 | 159,315 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
s=input()
print(s,end="")
for i in range(len(s)-1):
print(s[len(s)-2-i],end="")
print()
``` | instruction | 0 | 79,658 | 0 | 159,316 |
Yes | output | 1 | 79,658 | 0 | 159,317 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
given = input()
print(given, given[::-1], sep = "")
``` | instruction | 0 | 79,659 | 0 | 159,318 |
Yes | output | 1 | 79,659 | 0 | 159,319 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
o=input()
print(o+o[::-1])
``` | instruction | 0 | 79,660 | 0 | 159,320 |
Yes | output | 1 | 79,660 | 0 | 159,321 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
import math
from collections import OrderedDict
x = input()
if len(x)%2!=0:
check = 0
tu = list(x)
for i in range(math.floor(len(x)/2)):
if tu[i]==tu[len(x)-1-i]:
check+=1
else:
break
else:
check = 0
tu = list(x)
for i in range(int(len(x)/2)):
if tu[i]==tu[len(x)-1-i]:
check+=1
else:
break
if len(x)%2!=0:
if check==math.floor(len(x)/2):
print (x)
else:
io = list(x)
rt = list(OrderedDict.fromkeys(io))
print ("".join(rt))
else:
if check==int(len(x)/2):
print (x)
else:
io = list(x)
rt = list(OrderedDict.fromkeys(io))
if io==rt and len(io)==2:
rt.insert(0, rt[0])
rt.append(rt[0])
rt.append(rt[0])
print ("".join(rt))
``` | instruction | 0 | 79,661 | 0 | 159,322 |
No | output | 1 | 79,661 | 0 | 159,323 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
s = input()
print(s + s)
``` | instruction | 0 | 79,662 | 0 | 159,324 |
No | output | 1 | 79,662 | 0 | 159,325 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
x=input()
print(x[0],end='')
print(x[0])
``` | instruction | 0 | 79,663 | 0 | 159,326 |
No | output | 1 | 79,663 | 0 | 159,327 |
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 A. Find a string B, where B is a palindrome and A is a subsequence of B.
A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequence of "contest".
A palindrome is a string that reads the same forward or backward.
The length of string B should be at most 104. It is guaranteed that there always exists such string.
You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104.
Input
First line contains a string A (1 ≤ |A| ≤ 103) consisting of lowercase Latin letters, where |A| is a length of A.
Output
Output single line containing B consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string B should not exceed 104. If there are many possible B, print any of them.
Examples
Input
aba
Output
aba
Input
ab
Output
aabaa
Note
In the first example, "aba" is a subsequence of "aba" which is a palindrome.
In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
Submitted Solution:
```
s = input()
print(s, str(reversed(s)), sep="")
``` | instruction | 0 | 79,664 | 0 | 159,328 |
No | output | 1 | 79,664 | 0 | 159,329 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,987 | 0 | 159,974 |
Tags: implementation, math
Correct Solution:
```
a,b=input(),input()
bnb=b.count('1')%2
prefix=[int(a[0])]
for i in range(1,len(a)):
if a[i]=='1':
prefix.append(prefix[-1]+1)
else:
prefix.append(prefix[-1])
lb,la=len(b),len(a)
tot=1 if bnb==prefix[lb-1]%2 else 0
for j in range(lb,la):
pref=prefix[j]-prefix[j-lb]
if pref%2==bnb:
tot+=1
print(tot)
``` | output | 1 | 79,987 | 0 | 159,975 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,988 | 0 | 159,976 |
Tags: implementation, math
Correct Solution:
```
a = input()
b = input()
sum_a = sum(map(int, a[:len(b)]))
sum_b = sum(map(int, b))
count = 0
i = 0
while True:
xor = (sum_a + sum_b + 1) % 2
count += xor
if i >= len(a) - len(b):
break
sum_a = sum_a + int(a[i + len(b)]) - int(a[i])
i += 1
print(count)
``` | output | 1 | 79,988 | 0 | 159,977 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,989 | 0 | 159,978 |
Tags: implementation, math
Correct Solution:
```
a,b,res=input(),input(),0
sm1=sum(map(int,b[0:len(b)]))
sm2=sum(map(int,a[0:len(b)]))
res+=(sm1-sm2)%2==0
for i in range(len(b),len(a)):
sm2+=a[i]=='1'
sm2-=a[i-len(b)]=='1'
res+=(sm1-sm2)%2==0
print(res)
``` | output | 1 | 79,989 | 0 | 159,979 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,990 | 0 | 159,980 |
Tags: implementation, math
Correct Solution:
```
a=input()
b=input()
bo=b.count("1")
lb=len(b)
ao=a[:lb].count("1")
final_ans=0
if (ao+bo)%2==0:
final_ans+=1
for i in range(len(a)-lb):
if a[i]=="1":
ao-=1
if a[i+lb]=="1":
ao+=1
if (ao+bo)%2==0:
final_ans+=1
print(final_ans)
``` | output | 1 | 79,990 | 0 | 159,981 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,991 | 0 | 159,982 |
Tags: implementation, math
Correct Solution:
```
a = input()
b = input()
c = 0
for i in range(1, len(b)):
if b[i] != b[i-1]:
c += 1
s = 0
for i in range(len(b)):
if a[i]!=b[i]:
s += 1
ans = int(s&1==0)
for i in range(len(a)-len(b)):
s += c
if a[i] != b[0]:
s += 1
if a[i+len(b)] != b[-1]:
s += 1
ans += int(s&1==0)
print(ans)
``` | output | 1 | 79,991 | 0 | 159,983 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,992 | 0 | 159,984 |
Tags: implementation, math
Correct Solution:
```
r=input()
n=input()
length=len(n)
g=n.count("1")
same=False
nums=0
if len(r)<length:
print(0)
else:
if (r[:len(n)].count("1")-g) % 2 == 0:
same=True
nums+=1
for i in range(len(r)-len(n)):
if r[i]!=r[i+len(n)]:
same= not same
if same:
nums+=1
print(nums)
``` | output | 1 | 79,992 | 0 | 159,985 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,993 | 0 | 159,986 |
Tags: implementation, math
Correct Solution:
```
'''
fo=open("in.txt","r")
s1,s2=[l.strip('\n')for l in fo.readlines()]
print(s1,s2)
fo.close()
'''
#s1,s2=list(input(),input())
s1,s2=[input(),input()]
l1,l2=[len(s1),len(s2)]
cnt1,cnt2,l,p,ans=[0,0,0,0,0]
#print(l)
for i in s2:
if i=='1':
cnt2+=1
l+=1
for i in range(0,l1):
# print(i)
if s1[i]=='1':
cnt1+=1
p+=1
if p>l2:
if s1[i-l2]=='1':
cnt1-=1
if p>=l2:
if (abs(cnt1-cnt2)%2==0):
ans+=1
# print(i,' ',cnt1)
print(ans)
``` | output | 1 | 79,993 | 0 | 159,987 |
Provide tags and a correct Python 3 solution for this coding contest problem.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111. | instruction | 0 | 79,994 | 0 | 159,988 |
Tags: implementation, math
Correct Solution:
```
# AC
import sys
sys.setrecursionlimit(1000000)
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 = self.next_line()
self.index = 0
val = self.buff[self.index]
self.index += 1
return val
def next_line(self):
return sys.stdin.readline().split()
def next_ints(self):
return [int(x) for x in sys.stdin.readline().split()]
def next_int(self):
return int(self.next())
def solve(self):
a = self.next()
b = self.next()
d = 0
g = 0
for i in range(len(b)):
if a[i] != b[i]:
d += 1
if i > 0 and b[i] != b[i - 1]:
g += 1
ans = 1 if d % 2 == 0 else 0
for i in range(len(b), len(a)):
if a[i] != b[-1]:
d += 1
if a[i - len(b)] != b[0]:
d += 1
d += g
if d % 2 == 0:
ans += 1
print(ans)
if __name__ == '__main__':
Main().solve()
``` | output | 1 | 79,994 | 0 | 159,989 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111.
Submitted Solution:
```
from collections import deque
a=input()
b=input()
a1=len(a)
b1=len(b)
k=0
d=deque([])
for i in range(b1):
if a[i]!=b[i]:
k+=1
l=0
if k%2==0:
l+=1
#print(l)
if a1==b1:
print(l)
else:
for i in range(b1):
if a[i]==a[i+1]:
d.append(0)
else:
d.append(1)
m=sum(d)
k+=m
if k%2==0:
l+=1
#print(l)
for i in range(1,a1-b1):
m-=d[0]
d.popleft()
if a[i+b1]==a[i+b1-1]:
d.append(0)
else:
d.append(1)
m+=d[-1]
k+=m
if k%2==0:
l+=1
#print(l)
print(l)
``` | instruction | 0 | 79,995 | 0 | 159,990 |
Yes | output | 1 | 79,995 | 0 | 159,991 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111.
Submitted Solution:
```
import sys,math
def read_int():
return int(sys.stdin.readline().strip())
def read_int_list():
return list(map(int,sys.stdin.readline().strip().split()))
def read_string():
return sys.stdin.readline().strip()
def read_string_list(delim=" "):
return sys.stdin.readline().strip().split(delim)
def print_list(l):
print(" ".join(map(str, l)))
###### Author : Samir Vyas #######
###### Write Code Below #######
a = read_string()
b = read_string()
b_1 = sum([1 for i in b if i == "1"])
init_a_1 = sum([1 for i in a[:len(b)] if i == "1"])
count = 0
count += (b_1%2 == init_a_1%2)
for i in range(len(b),len(a)):
init_a_1 -= int(a[i-len(b)])
init_a_1 += int(a[i])
count += (b_1%2 == init_a_1%2)
print(count)
``` | instruction | 0 | 79,996 | 0 | 159,992 |
Yes | output | 1 | 79,996 | 0 | 159,993 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111.
Submitted Solution:
```
s1 = input()
s2 = input()
ans = 0
tot = 0
for i in range(len(s2)):
tot += s1[i] != s2[i]
ans += tot % 2 == 0
for i in range(len(s2) , len(s1)):
tot += s1[i] != s1[i - len(s2)]
ans += tot % 2 == 0
print(ans)
``` | instruction | 0 | 79,997 | 0 | 159,994 |
Yes | output | 1 | 79,997 | 0 | 159,995 |
Evaluate the correctness of the submitted Python 3 solution to the coding contest problem. Provide a "Yes" or "No" response.
Vus the Cossack has two binary strings, that is, strings that consist only of "0" and "1". We call these strings a and b. It is known that |b| ≤ |a|, that is, the length of b is at most the length of a.
The Cossack considers every substring of length |b| in string a. Let's call this substring c. He matches the corresponding characters in b and c, after which he counts the number of positions where the two strings are different. We call this function f(b, c).
For example, let b = 00110, and c = 11000. In these strings, the first, second, third and fourth positions are different.
Vus the Cossack counts the number of such substrings c such that f(b, c) is even.
For example, let a = 01100010 and b = 00110. a has four substrings of the length |b|: 01100, 11000, 10001, 00010.
* f(00110, 01100) = 2;
* f(00110, 11000) = 4;
* f(00110, 10001) = 4;
* f(00110, 00010) = 1.
Since in three substrings, f(b, c) is even, the answer is 3.
Vus can not find the answer for big strings. That is why he is asking you to help him.
Input
The first line contains a binary string a (1 ≤ |a| ≤ 10^6) — the first string.
The second line contains a binary string b (1 ≤ |b| ≤ |a|) — the second string.
Output
Print one number — the answer.
Examples
Input
01100010
00110
Output
3
Input
1010111110
0110
Output
4
Note
The first example is explained in the legend.
In the second example, there are five substrings that satisfy us: 1010, 0101, 1111, 1111.
Submitted Solution:
```
import sys
input = sys.stdin.readline
a, b, res, ca, cb = input()[:-1], input()[:-1], 0, 0, 0; lb, la = len(b), len(a)
for i in range(lb):
if a[i] == '1': ca += 1
if b[i] == '1': cb += 1
if ca % 2 == cb % 2: res += 1
for i in range(lb, la):
if a[i] == '1': ca += 1
if a[i - lb] == '1': ca += 1
if ca % 2 == cb % 2: res += 1
print(res)
``` | instruction | 0 | 79,998 | 0 | 159,996 |
Yes | output | 1 | 79,998 | 0 | 159,997 |
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