A14084. Split it!
编程题
普及/提高-
知识点
题目描述
Kawashiro Nitori is a girl who loves competitive programming.
One day she found a string and an integer. As an advanced problem setter, she quickly thought of a problem.
Given a string $s$ and a parameter $k$ , you need to check if there exist $k+1$ non-empty strings $a_1,a_2...,a_{k+1}$ , such that $s=a_1+a_2+\ldots +a_k+a_{k+1}+R(a_k)+R(a_{k-1})+\ldots+R(a_{1}).$ Here $+$ represents concatenation. We define $R(x)$ as a reversed string $x$ . For example $R(abcd) = dcba$ . Note that in the formula above the part $R(a\_{k+1})$$$ is intentionally skipped.
One day she found a string and an integer. As an advanced problem setter, she quickly thought of a problem.
Given a string $s$ and a parameter $k$ , you need to check if there exist $k+1$ non-empty strings $a_1,a_2...,a_{k+1}$ , such that $s=a_1+a_2+\ldots +a_k+a_{k+1}+R(a_k)+R(a_{k-1})+\ldots+R(a_{1}).$ Here $+$ represents concatenation. We define $R(x)$ as a reversed string $x$ . For example $R(abcd) = dcba$ . Note that in the formula above the part $R(a\_{k+1})$$$ is intentionally skipped.
输入格式
The input consists of multiple test cases. The first line contains a single integer $t$ ( $1\le t\le 100$ ) — the number of test cases. The description of the test cases follows.
The first line of each test case description contains two integers $n$ , $k$ ( $1\le n\le 100$ , $0\le k\le \lfloor \frac{n}{2} \rfloor$ ) — the length of the string $s$ and the parameter $k$ .
The second line of each test case description contains a single string $s$ of length $n$ , consisting of lowercase English letters.
The first line of each test case description contains two integers $n$ , $k$ ( $1\le n\le 100$ , $0\le k\le \lfloor \frac{n}{2} \rfloor$ ) — the length of the string $s$ and the parameter $k$ .
The second line of each test case description contains a single string $s$ of length $n$ , consisting of lowercase English letters.
输出格式
For each test case, print "YES" (without quotes), if it is possible to find $a_1,a_2,\ldots,a_{k+1}$ , and "NO" (without quotes) otherwise.
You can print letters in any case (upper or lower).
You can print letters in any case (upper or lower).
输入输出样例
输入 #1
7 5 1 qwqwq 2 1 ab 3 1 ioi 4 2 icpc 22 0 dokidokiliteratureclub 19 8 imteamshanghaialice 6 3 aaaaaa
输出 #1
YES NO YES NO YES NO NO
说明/提示
In the first test case, one possible solution is $a_1=qw$ and $a_2=q$ .
In the third test case, one possible solution is $a_1=i$ and $a_2=o$ .
In the fifth test case, one possible solution is $a_1=dokidokiliteratureclub$ .
In the third test case, one possible solution is $a_1=i$ and $a_2=o$ .
In the fifth test case, one possible solution is $a_1=dokidokiliteratureclub$ .