Problems > Is This Slice Sorted

Is This Slice Sorted

Difficulty: 2100 4000 ms 128 MB

prefix-sums

Answer Q queries: is the subarray al..r non-decreasing?

Input: the first line has N and Q; the second line has the array; the next Q lines have l and r.

Output: one line per query: YES or NO.

Constraints:

  • 1 ≤ N, Q ≤ 105

Sample Tests

Input 1
5 3
1 2 2 1 3
1 3
3 5
4 5
Output 1
YES
NO
YES
Input 2
1 1
5
1 1
Output 2
YES

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