CF1851C.Tiles Comeback

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题目描述

Vlad remembered that he had a series of nn tiles and a number kk . The tiles were numbered from left to right, and the ii -th tile had colour cic_i .

If you stand on the first tile and start jumping any number of tiles right, you can get a path of length pp . The length of the path is the number of tiles you stood on.

Vlad wants to see if it is possible to get a path of length pp such that:

  • it ends at tile with index nn ;
  • pp is divisible by kk
  • the path is divided into blocks of length exactly kk each;
  • tiles in each block have the same colour, the colors in adjacent blocks are not necessarily different.

For example, let n=14n = 14 , k=3k = 3 .

The colours of the tiles are contained in the array cc = [ 1,2,1,1,7,5,3,3,1,3,4,4,2,4\color{red}{1}, \color{violet}{2}, \color{red}{1}, \color{red}{1}, \color{gray}{7}, \color{orange}{5}, \color{green}{3}, \color{green}{3}, \color{red}{1}, \color{green}{3}, \color{blue}{4}, \color{blue}{4}, \color{violet}{2}, \color{blue}{4} ]. Then we can construct a path of length 66 consisting of 22 blocks:

c1c3c4c11c12c14\color{red}{c_1} \rightarrow \color{red}{c_3} \rightarrow \color{red}{c_4} \rightarrow \color{blue}{c_{11}} \rightarrow \color{blue}{c_{12}} \rightarrow \color{blue}{c_{14}}

All tiles from the 11 -st block will have colour 1\color{red}{\textbf{1}} , from the 22 -nd block will have colour 4\color{blue}{\textbf{4}} .

It is also possible to construct a path of length 99 in this example, in which all tiles from the 11 -st block will have colour 1\color{red}{\textbf{1}} , from the 22 -nd block will have colour 3\color{green}{\textbf{3}} , and from the 33 -rd block will have colour 4\color{blue}{\textbf{4}} .

输入格式

The first line of input data contains a single integer tt ( 1t1041 \le t \le 10^4 ) — the number of test cases.

The description of the test cases follows.

The first line of each test case contains two integers nn and kk ( 1kn21051 \le k \le n \le 2 \cdot 10^5 )—the number of tiles in the series and the length of the block.

The second line of each test case contains nn integers c1,c2,c3,,cnc_1, c_2, c_3, \dots, c_n ( 1cin1 \le c_i \le n ) — the colours of the tiles.

It is guaranteed that the sum of nn over all test cases does not exceed 21052 \cdot 10^5 .

输出格式

For each test case, output on a separate line:

  • YES if you can get a path that satisfies these conditions;
  • NO otherwise.

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

输入输出样例

  • 输入#1

    10
    4 2
    1 1 1 1
    14 3
    1 2 1 1 7 5 3 3 1 3 4 4 2 4
    3 3
    3 1 3
    10 4
    1 2 1 2 1 2 1 2 1 2
    6 2
    1 3 4 1 6 6
    2 2
    1 1
    4 2
    2 1 1 1
    2 1
    1 2
    3 2
    2 2 2
    4 1
    1 1 2 2

    输出#1

    YES
    YES
    NO
    NO
    YES
    YES
    NO
    YES
    YES
    YES

说明/提示

In the first test case, you can jump from the first tile to the last tile;

The second test case is explained in the problem statement.

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