CF1867D.Cyclic Operations

普及+/提高

通过率:0%

时间限制:1.00s

内存限制:256MB

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题目描述

Egor has an array aa of length nn, initially consisting of zeros. However, he wanted to turn it into another array bb of length nn.

Since Egor doesn't take easy paths, only the following operation can be used (possibly zero or several times):

  • choose an array ll of length kk (1≤li≤n1 \leq l_i \leq n, all lil_i are distinct) and change each element alia_{l_i} to l(i%k)+1l_{(i\%k)+1} (1≤i≤k1 \leq i \leq k).

He became interested in whether it is possible to get the array bb using only these operations. Since Egor is still a beginner programmer, he asked you to help him solve this problem.

The operation %\% means taking the remainder, that is, a%ba\%b is equal to the remainder of dividing the number aa by the number bb.

叶戈尔有一个长度为 nn 的数组 aa,初始时所有元素均为 00。但他希望将其变为另一个长度为 nn 的数组 bb。

由于叶戈尔从不走捷径,他只允许使用以下操作(可执行零次或多次):

  • 选择一个长度为 kk 的数组 ll(满足 1≤li≤n1 \leq l_i \leq n,且所有 lil_i 互不相同),并将每个元素 alia_{l_i} 修改为 l(i%k)+1l_{(i\%k)+1}(其中 1≤i≤k1 \leq i \leq k)。

他开始好奇:仅通过这些操作,是否可能得到数组 bb?由于叶戈尔仍是一名初学编程者,他请你帮助他解决这个问题。

运算符 %\% 表示取模运算,即 a%ba\%b 表示 aa 除以 bb 所得的余数。

输入格式

The first line of the input contains an integer tt (1≤t≤1051 \leq t \leq 10^5) - the number of test cases.

Each test case consists of two lines. The first line contains two integers nn and kk (1≤k≤n≤1051 \leq k \leq n \leq 10^5).

The second line contains the array b1,b2,…,bnb_1, b_2, \ldots, b_n (1≤bi≤n1 \leq b_i \leq n).

It is guaranteed that the sum of nn over all test cases does not exceed 2⋅1052 \cdot 10^5.

输入的第一行包含一个整数 tt(1≤t≤1051 \leq t \leq 10^5),表示测试用例的数量。

每个测试用例由两行组成。第一行包含两个整数 nn 和 kk(1≤k≤n≤1051 \leq k \leq n \leq 10^5)。

第二行包含数组 b1,b2,…,bnb_1, b_2, \ldots, b_n(1≤bi≤n1 \leq b_i \leq n)。

保证所有测试用例的 nn 之和不超过 2⋅1052 \cdot 10^5。

输出格式

For each test case, output "YES" (without quotes) if there is a way to get the array bb using only the given operation. Otherwise, output "NO" (without quotes). You can output each letter in any case (lowercase or uppercase). For example, the strings "yEs", "yes", "Yes" and "YES" will be accepted as a positive answer.

对于每个测试用例,如果仅使用给定操作就能得到数组 bb,则输出 "YES"(不带引号);否则输出 "NO"(不带引号)。每个字母可为任意大小写(小写或大写)。例如,字符串 "yEs"、"yes"、"Yes" 和 "YES" 均被视为正确的肯定回答。

输入输出样例

  • 输入#1

    6
    5 3
    2 3 5 3 4
    4 2
    2 4 3 1
    1 1
    1
    3 1
    1 2 3
    5 3
    5 4 3 2 1
    6 1
    1 2 3 1 5 6

    输出#1

    YES
    NO
    YES
    YES
    NO
    NO

说明/提示

Let's consider the first example:

  • Apply the operation with ll = [1,2,3][1,2,3]. Now aa = [2,3,1,0,0][2,3,1,0,0].
  • Apply the operation with ll = [3,5,4][3,5,4]. Now aa = [2,3,5,3,4][2,3,5,3,4] = bb.

We see that it is possible to get the array bb. Therefore, the answer is YES.

In the second example, it can be proven that the array bb cannot be obtained, therefore the answer is NO.

我们考虑第一个例子:

  • 对 l=[1,2,3]l = [1,2,3] 执行该操作。此时 a=[2,3,1,0,0]a = [2,3,1,0,0]。
  • 对 l=[3,5,4]l = [3,5,4] 执行该操作。此时 a=[2,3,5,3,4]=ba = [2,3,5,3,4] = b。

我们发现可以得到数组 bb。因此,答案是 YES。

在第二个例子中,可以证明无法得到数组 bb,因此答案是 NO。

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