Cubes Sorting SOLUTION Codeforces Round #672 (Div. 2)
Wheatley chose to attempt to make a test chamber. He made a pleasant test chamber, yet there was just one detail missing — solid shapes.
For finishing the chamber Wheatley needs n solid shapes. I-th 3D square has a volume ai.
Wheatley needs to put solid shapes so that they would be arranged in a non-diminishing request by their volume. Officially, for each i>1, ai−1≤ai must hold.
To accomplish his objective, Wheatley can trade two neighboring shapes. It implies that for any i>1 you can trade 3D squares on positions i−1 and I.
Be that as it may, there is an issue: Wheatley is fretful. On the off chance that Wheatley needs more than n⋅(n−1)2−1 trade activities, he won’t accomplish this exhausting work.
Wheatly needs to know: can blocks be arranged under this conditions?
Each test contains different experiments.
The main line contains one sure number t (1≤t≤1000), indicating the quantity of experiments. Portrayal of the experiments follows.
The principal line of each experiment contains one sure whole number n (2≤n≤5⋅104) — number of blocks.
The subsequent line contains n positive numbers ai (1≤ai≤109) — volumes of 3D shapes.
It is ensured that the entirety of n over all experiments doesn’t surpass 105.
For each experiment, print a word in a solitary line: “YES” (without quotes) if the 3D squares can be arranged and “NO” (without quotes) in any case.
5 3 2 1 4
In the primary experiment it is conceivable to sort all the shapes in 7 trades.
In the subsequent experiment the 3D shapes are as of now arranged.
In the third experiment we can make 0 trades, however the blocks are not arranged at this point, so the appropriate response is “NO”.