Array of Beauty
Time Limit: 2.0 s
Memory Limit: 256.0 MB
Description
Rayhan wants to give a special gift to his friends Abidur and Binoy. They both love beautiful arrays, where an array is called beautiful if it is sorted in non-decreasing order.
Rayhan has an array A of size n. He wants to create a new array B using the following rules:
- In each move, he can remove either the first or the last element of array A.
- He must insert the removed element either at the beginning or at the end of array B.
The goal is to make array B beautiful (non-decreasing) after all elements of A have been moved.
Determine if Rayhan can create such a beautiful array B for his friends.
Print "YES" if possible, otherwise print "NO".
Input
Each test contains multiple test cases. The first line contains the number of test cases
\(t (1 ≤ t ≤ 10^4)\). The description of the test cases follows.
The first line of each test case contains an integer \(n (1 ≤ n <= 10^5)\) the length of A.
The second line contains \(n\) integers \(A_1, A_2, ..., A_n (1 ≤ A_i ≤ 10^9)\) — the elements of array A.
It is guaranteed that the sum of n over all test cases does not exceed \(2*10^5\)
Output
For each test case, print "YES" if it is possible to create a beautiful array B, otherwise print "NO".
Sample
Input | Output |
---|---|
|
|
Case 1: A = [1, 3, 2]
● Take 1 from the front of A and insert it back of B → B = [1], A = [3, 2].
● Take 2 from the back of A and insert it back of B → B = [1, 2], A = [3].
● Take 3 from the front of A and insert it back of B → B = [1, 2, 3], A = [].
Final B = [1, 2, 3] is sorted non-decreasing order → YES.
Case 3: A = [4, 3, 1, 2]
● Take 4 from the front of A and insert it back of B → B = [4], A = [3, 1, 2].
● Take 3 from the front of A and insert it in front of B → B = [3, 4], A = [1, 2].
● Take 2 from the back of A and insert it in front of B → B = [2, 3, 4], A = [1].
● Take 1 from the front of A and insert it in front of B → B = [1, 2, 3, 4], A = [].
Final B = [1, 2, 3, 4] is sorted non-decreasing order → YES.
Information
- ID
- 1229
- Difficulty
- 9
- Category
- (None)
- Tags
- (None)
- # Submissions
- 85
- Accepted
- 3
- Accepted Ratio
- 4%
- Uploaded By