Codeforces Round 672 (Div. 2) |
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Finished |
Oh, that's funny, is it? Oh it's funny? Because we've been at this for twelve hours and you haven't solved it either, so I don't know why you're laughing. You've got one hour! Solve it!
Wheatley decided to try to make a test chamber. He made a nice test chamber, but there was only one detail absent — cubes.
For completing the chamber Wheatley needs $$$n$$$ cubes. $$$i$$$-th cube has a volume $$$a_i$$$.
Wheatley has to place cubes in such a way that they would be sorted in a non-decreasing order by their volume. Formally, for each $$$i>1$$$, $$$a_{i-1} \le a_i$$$ must hold.
To achieve his goal, Wheatley can exchange two neighbouring cubes. It means that for any $$$i>1$$$ you can exchange cubes on positions $$$i-1$$$ and $$$i$$$.
But there is a problem: Wheatley is very impatient. If Wheatley needs more than $$$\frac{n \cdot (n-1)}{2}-1$$$ exchange operations, he won't do this boring work.
Wheatly wants to know: can cubes be sorted under this conditions?
Each test contains multiple test cases.
The first line contains one positive integer $$$t$$$ ($$$1 \le t \le 1000$$$), denoting the number of test cases. Description of the test cases follows.
The first line of each test case contains one positive integer $$$n$$$ ($$$2 \le n \le 5 \cdot 10^4$$$) — number of cubes.
The second line contains $$$n$$$ positive integers $$$a_i$$$ ($$$1 \le a_i \le 10^9$$$) — volumes of cubes.
It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$10^5$$$.
For each test case, print a word in a single line: "YES" (without quotation marks) if the cubes can be sorted and "NO" (without quotation marks) otherwise.
3 5 5 3 2 1 4 6 2 2 2 2 2 2 2 2 1
YES YES NO
In the first test case it is possible to sort all the cubes in $$$7$$$ exchanges.
In the second test case the cubes are already sorted.
In the third test case we can make $$$0$$$ exchanges, but the cubes are not sorted yet, so the answer is "NO".
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