CF1545A.AquaMoon and Strange Sort

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

AquaMoon has nn friends. They stand in a row from left to right, and the ii -th friend from the left wears a T-shirt with a number aia_i written on it. Each friend has a direction (left or right). In the beginning, the direction of each friend is right.

AquaMoon can make some operations on friends. On each operation, AquaMoon can choose two adjacent friends and swap their positions. After each operation, the direction of both chosen friends will also be flipped: left to right and vice versa.

AquaMoon hopes that after some operations, the numbers written on the T-shirt of nn friends in the row, read from left to right, become non-decreasing. Also she wants, that all friends will have a direction of right at the end. Please find if it is possible.

输入格式

The input consists of multiple test cases. The first line contains a single integer tt ( 1t501 \leq t \leq 50 ) — the number of test cases.

The first line of each test case contains a single integer nn ( 1n1051 \leq n \leq 10^5 ) — the number of Aquamoon's friends.

The second line contains nn integers a1,a2,,ana_1, a_2, \dots, a_n ( 1ai1051 \leq a_i \leq 10^5 ) — the numbers, written on the T-shirts.

It is guaranteed that the sum of nn for all test cases does not exceed 10510^5 .

输出格式

For each test case, if there exists a possible sequence of operations, print "YES" (without quotes); otherwise, print "NO" (without quotes).

You can print each letter in any case (upper or lower).

输入输出样例

  • 输入#1

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

    输出#1

    YES
    YES
    NO

说明/提示

The possible list of operations in the first test case:

  1. Swap a1a_1 and a2a_2 . The resulting sequence is 3,4,2,53, 4, 2, 5 . The directions are: left, left, right, right.
  2. Swap a2a_2 and a3a_3 . The resulting sequence is 3,2,4,53, 2, 4, 5 . The directions are: left, left, right, right.
  3. Swap a1a_1 and a2a_2 . The resulting sequence is 2,3,4,52, 3, 4, 5 . The directions are: right, right, right, right.
首页