Codeforces Round 853 (Div. 2)
B
Serval and Inversion Magic
Codeforces
800
原题
← AC →
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Serval has a string $s$ that only consists of 0 and 1 of length $n$. The $i$-th character of $s$ is denoted as $s_i$, where $1\leq i\leq n$.

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Serval can perform the following operation called Inversion Magic on the string $s$:

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  • Choose an segment $[l, r]$ ($1\leq l\leq r\leq n$). For $l\leq i\leq r$, change $s_i$ into 1 if $s_i$ is 0, and change $s_i$ into 0 if $s_i$ is 1.
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For example, let $s$ be 010100 and the segment $[2,5]$ is chosen. The string $s$ will be 001010 after performing the Inversion Magic.

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Serval wants to make $s$ a palindrome after performing Inversion Magic exactly once. Help him to determine whether it is possible.

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A string is a palindrome iff it reads the same backwards as forwards. For example, 010010 is a palindrome but 10111 is not.

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1\leq t\leq 10^4$). The description of the test cases follows.

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The first line of each test case contains a single integer $n$ ($2\leq n\leq 10^5$) — the length of string $s$.

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The second line of each test case contains a binary string $s$ of length $n$. Only characters 0 and 1 can appear in $s$.

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It's guaranteed that the sum of $n$ over all test cases does not exceed $2\cdot 10^5$.

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Output

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For each test case, print Yes if $s$ can be a palindrome after performing Inversion Magic exactly once, and print No if not.

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You can output Yes and No in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive response).

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Note

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In the first test case, Serval can perform Inversion Magic on the segment $[1,4]$. The string $s$ will be 0110 after the magic.

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In the second test case, Serval can perform Inversion Magic on the segment $[1,3]$. The string $s$ will be 01110 after the magic.

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In the third test case, Serval can't make $s$ a palindrome by performing Inversion Magic exactly once.

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样例

Input #1
3
4
1001
5
10010
7
0111011
Output #1
Yes
Yes
No
InputCopy OutputCopy
题目信息
题号
1789B
时间限制
1 s
内存限制
256 MB
标签
暴力
模拟
字符串
双指针

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。