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Luka and Permutation

1000ms 65536K

Description:

Luka has a sequence $$$p = { p_1, p_2, \cdots , p_N }$$$ which is a permutation of $$$ {1, 2, \cdots, N} $$$.

However, there are some naughty numbers which is not at its position, that is to say, $$$p_i \neq i $$$. Luka is a perfectionist so he can choose two integers $$$i$$$ and $$$j$$$ ($$$1 \leq i < j \leq N$$$) and swap $$$p_i$$$ and $$$p_j$$$. But he is a little bit lazy so that he just want to do this operation once. Help him calculate if he can sort $$$p$$$ in ascending order.

Input:

The first lines contains an integer $$$T$$$ means the number of test cases.

For each test case, the first line contains one integer $$$N$$$ describes the length of the sequence and the second line contain $$$N$$$ non-repeating integer forming sequence $$$p$$$.

Note that: $$$1 \leq T \leq 100 $$$, $$$1 \leq N \leq 10^5 $$$. And the sum of all $$$N$$$ would not exceed $$$ 10^6 $$$.

Output:

For each test case, output one single line of YES or NO.

Sample Input:

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

Sample Output:

YES
NO

Info

NOJ

Provider NOJ

Code NOJ2385

Tags

Submitted 53

Passed 29

AC Rate 54.72%

Date 08/15/2019 01:18:45

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