Codeforces Round 786 (Div. 3) |
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Finished |
You are given three arrays $$$a$$$, $$$b$$$ and $$$c$$$. Initially, array $$$a$$$ consists of $$$n$$$ elements, arrays $$$b$$$ and $$$c$$$ are empty.
You are performing the following algorithm that consists of two steps:
Can you make array $$$c$$$ sorted in non-decreasing order?
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 2 \cdot 10^4$$$) — the number of test cases. Next $$$t$$$ cases follow.
The first line of each test case contains the single integer $$$n$$$ ($$$1 \le n \le 2 \cdot 10^5$$$) — the length of array $$$a$$$.
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \dots, a_n$$$ ($$$1 \le a_i \le 10^6$$$) — the array $$$a$$$ itself.
It's guaranteed that the sum of $$$n$$$ doesn't exceed $$$2 \cdot 10^5$$$.
For each test, print YES (case-insensitive), if you can make array $$$c$$$ sorted in non-decreasing order. Otherwise, print NO (case-insensitive).
343 1 5 333 2 117331
YES NO YES
In the first test case, we can do the following for $$$a = [3, 1, 5, 3]$$$:
Step $$$1$$$:
$$$a$$$ | $$$[3, 1, 5, 3]$$$ | $$$\Rightarrow$$$ | $$$[3, 1, 5]$$$ | $$$\Rightarrow$$$ | $$$[3, 1]$$$ | $$$\Rightarrow$$$ | $$$[3]$$$ | $$$\Rightarrow$$$ | $$$[]$$$ |
$$$b$$$ | $$$[]$$$ | $$$[\underline{3}]$$$ | $$$[3, \underline{5}]$$$ | $$$[3, \underline{1}, 5]$$$ | $$$[3, \underline{3}, 1, 5]$$$ |
Step $$$2$$$:
$$$b$$$ | $$$[3, 3, \underline{1}, 5]$$$ | $$$\Rightarrow$$$ | $$$[3, \underline{3}, 5]$$$ | $$$\Rightarrow$$$ | $$$[\underline{3}, 5]$$$ | $$$\Rightarrow$$$ | $$$[\underline{5}]$$$ | $$$\Rightarrow$$$ | $$$[]$$$ |
$$$c$$$ | $$$[]$$$ | $$$[1]$$$ | $$$[1, 3]$$$ | $$$[1, 3, 3]$$$ | $$$[1, 3, 3, 5]$$$ |
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