AtCoder Regular Contest 155
A
ST and TS Palindrome
AtCoder
⌀ 1548
原题
←B →
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Problem Statement

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You are given a string $S$ of length $N$ consisting of lowercase English letters, and a positive integer $K$.

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Determine whether there is a string $S'$ of length $K$ that satisfies the following conditions.

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  • The concatenation of $S$ and $S'$ in this order is a palindrome.
  • The concatenation of $S'$ and $S$ in this order is a palindrome.
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You have $T$ test cases to solve.

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Constraints

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  • $1 \leq T \leq 10^5$
  • $1 \leq N \leq 2 \times 10^5$
  • $1 \leq K \leq 10^{18}$
  • $S$ is a string of length $N$ consisting of lowercase English letters.
  • All numbers in the input are integers.
  • In each input file, the sum of $N$ over the test cases is at most $2 \times 10^5$.
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Input

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The input is given from Standard Input in the following format:

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T
\mathrm{case}_1
\vdots
\mathrm{case}_T

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Each case is in the following format:

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N K
S

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Output

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Print $T$ lines. The $i$-th line should contain Yes if there is a string $S'$ that satisfies the conditions for the $i$-th test case, and No otherwise.

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样例

Input #1
2
6 2
abbaab
5 3
abcbb
Output #1
Yes
No
For the first test case, if we let $S' = {}$`ba`, for instance, the concatenation of $S$ and $S'$ in this order will be `abbaabba`, which is a palindrome. Here, the concatenation of $S'$ and $S$ in this order is `baabbaab`, which is also a palindrome. Thus, $S' = {}$`ba` satisfies the condition, so the answer is `Yes`. For the second test case, we can prove that no string satisfies the conditions.
Input #2
3
12 400378271514996652
njvhhvjnnjvh
10 884633988115575508
rrhiyvrrur
36 71630165869626180
vsxmxajrrduhhudrrjaxmxsvvsxmxajrrduh
Output #2
Yes
No
Yes
题目信息
题号
arc155_a
时间限制
2 s
内存限制
1024 MB

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