A14084 | Split it!

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.

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.

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).