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CF1891A.Sorting with Twos
Sorting with Twos
You are given an array of integers . In one operation, you do the following:
- Choose a non-negative integer , such that .
- Subtract from for all integers , such that .
Can you sort the array in non-decreasing order by performing some number (possibly zero) of operations?
An array is considered non-decreasing if for all integers such that .
Input
The first line contains a single integer () — the number of test cases. The description of the test cases follows.
The first line of each test case contains a single integer () — the length of array .
The second line of each test case contains integers — the integers in array ().
Output
For each test case, output "YES" if the array can be sorted, and "NO" otherwise.
Note
In the first test case, the array is already sorted in non-decreasing order, so we don't have to perform any operations.
In the second test case, we can choose twice to get the array . Then, we can choose once and get the sorted in non-decreasing order array .
In the third test case, we can choose once and get the array . Then, we can choose twice and get the array . After that, we can choose once and get the sorted in non-decreasing order array .
For the fourth and fifth test case, it can be shown that the array could not be sorted using these operations.
Samples
8
5
1 2 3 4 5
5
6 5 3 4 4
9
6 5 5 7 5 6 6 8 7
4
4 3 2 1
6
2 2 4 5 3 2
8
1 3 17 19 27 57 179 13
5
3 17 57 179 92
10
1 2 3 4 0 6 7 8 9 10
YES
YES
YES
NO
NO
NO
YES
YES
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