Larry's Array

Larry has been given a permutation of a sequence of natural numbers incrementing from  as an array. He must determine whether the array can be sorted using the following operation any number of times:

• Choose any  consecutive indices and rotate their elements in such a way that .

For example, if :

A  rotate 
[1,6,5,2,4,3] [6,5,2]
[1,5,2,6,4,3] [5,2,6]
[1,2,6,5,4,3] [5,4,3]
[1,2,6,3,5,4] [6,3,5]
[1,2,3,5,6,4] [5,6,4]
[1,2,3,4,5,6]

YES

On a new line for each test case, print YES if  can be fully sorted. Otherwise, print NO.

Function Description

Complete the larrysArray function in the editor below. It must return a string, either YES or NO.

larrysArray has the following parameter(s):

• A: an array of integers

Input Format

The first line contains an integer , the number of test cases.

The next  pairs of lines are as follows:

• The first line contains an integer , the length of .
• The next line contains  space-separated integers .

Constraints

•  integers that increment by  from  to 

Output Format

For each test case, print YES if  can be fully sorted. Otherwise, print NO.

Sample Input

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

Sample Output

YES
YES
NO

Explanation

In the explanation below, the subscript of  denotes the number of operations performed.

Test Case 0:

 is now sorted, so we print  on a new line.

Test Case 1:
.
.
 is now sorted, so we print  on a new line.

Test Case 2:
No sequence of rotations will result in a sorted . Thus, we print  on a new line.

php

<?php

// Complete the larrysArray function below.

function larrysArray($A) {

$cninversion = 0;

for($i =0; $i < count($A)-1; $i++){

for($j =$i+1; $j < count($A); $j++)

{

if($A[$i] > $A[$j])

$cninversion++;

}

}

if($cninversion%2 == 0)

return 'YES';

return 'NO';

}

$fptr = fopen(getenv("OUTPUT_PATH"), "w");

$stdin = fopen("php://stdin", "r");

fscanf($stdin, "%d\n", $t);

for ($t_itr = 0; $t_itr < $t; $t_itr++) {

fscanf($stdin, "%d\n", $n);

fscanf($stdin, "%[^\n]", $A_temp);

$A = array_map('intval',

preg_split('/ /', $A_temp, -1, PREG_SPLIT_NO_EMPTY));

$result = larrysArray($A);

fwrite($fptr, $result . "\n");

}

fclose($stdin);

fclose($fptr);