Codeforces Round 746 (Div. 2)
B
Hemose Shopping
Codeforces
1200
原题
← AC →
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Hemose was shopping with his friends Samez, AhmedZ, AshrafEzz, TheSawan and O_E in Germany. As you know, Hemose and his friends are problem solvers, so they are very clever. Therefore, they will go to all discount markets in Germany.

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Hemose has an array of $n$ integers. He wants Samez to sort the array in the non-decreasing order. Since it would be a too easy problem for Samez, Hemose allows Samez to use only the following operation:

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  • Choose indices $i$ and $j$ such that $1 \le i, j \le n$, and $\lvert i - j \rvert \geq x$. Then, swap elements $a_i$ and $a_j$.
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Can you tell Samez if there's a way to sort the array in the non-decreasing order by using the operation written above some finite number of times (possibly $0$)?

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ $(1 \leq t \leq 10^5)$. Description of the test cases follows.

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The first line of each test case contains two integers $n$ and $x$ $(1 \leq x \leq n \leq 10^5)$.

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The second line of each test case contains $n$ integers $a_1, a_2, ..., a_n$ $(1 \leq a_i \leq 10^9)$.

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It is guaranteed that the sum of $n$ over all test cases doesn't exceed $2 \cdot 10^5$.

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Output

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For each test case, you should output a single string.

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If Samez can sort the array in non-decreasing order using the operation written above, output "YES" (without quotes). Otherwise, output "NO" (without quotes).

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You can print each letter of "YES" and "NO" in any case (upper or lower).

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Note

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In the first test case, you can't do any operations.

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In the second test case, the array is already sorted.

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In the third test case, you can do the operations as follows:

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  • $[5,1,2,3,4]$, $swap(a_1,a_3)$
  • $[2,1,5,3,4]$, $swap(a_2,a_5)$
  • $[2,4,5,3,1]$, $swap(a_2,a_4)$
  • $[2,3,5,4,1]$, $swap(a_1,a_5)$
  • $[1,3,5,4,2]$, $swap(a_2,a_5)$
  • $[1,2,5,4,3]$, $swap(a_3,a_5)$
  • $[1,2,3,4,5]$
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(Here $swap(a_i, a_j)$ refers to swapping elements at positions $i$, $j$).

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样例

Input #1
4
3 3
3 2 1
4 3
1 2 3 4
5 2
5 1 2 3 4
5 4
1 2 3 4 4
Output #1
NO
YES
YES
YES
InputCopy OutputCopy
题目信息
题号
1592B
时间限制
1 s
内存限制
256 MB
标签
构造
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数学
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题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。