CF1496A.Split it!

普及/提高-

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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 ss and a parameter kk , you need to check if there exist k+1k+1 non-empty strings a1,a2...,ak+1a_1,a_2...,a_{k+1} , such that s=a1+a2++ak+ak+1+R(ak)+R(ak1)++R(a1).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)R(x) as a reversed string xx . For example R(abcd)=dcbaR(abcd) = dcba . Note that in the formula above the part R(a_k+1)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 tt ( 1t1001\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 nn , kk ( 1n1001\le n\le 100 , 0kn20\le k\le \lfloor \frac{n}{2} \rfloor ) — the length of the string ss and the parameter kk .

The second line of each test case description contains a single string ss of length nn , consisting of lowercase English letters.

输出格式

For each test case, print "YES" (without quotes), if it is possible to find a1,a2,,ak+1a_1,a_2,\ldots,a_{k+1} , and "NO" (without quotes) otherwise.

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 a1=qwa_1=qw and a2=qa_2=q .

In the third test case, one possible solution is a1=ia_1=i and a2=oa_2=o .

In the fifth test case, one possible solution is a1=dokidokiliteraturecluba_1=dokidokiliteratureclub .

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