COCI '20 Contest 6 #5 Index

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Points: 15 (partial)
Time limit: 2.5s
Memory limit: 512M

Problem type

The h-index is an author-level metric that measures both the productivity and citation impact of the publications of a scientist or scholar. It is defined as the maximum value of h such that the given author has published h papers that have each been cited at least h times.

Our Mirko is nearing retirement. In his life he had published n papers and now q times he asks himself the following:

I wonder, what would be my h-index had I only published papers li through ri?

Help him calculate the answers.

Input Specification

The first line contains integers n and q (1n,q200000), the number of papers and the number of questions.

The second line contains n integers pi (1pi200000), where pi is the number of citations of the ith paper.

The following q lines each contain two integers li and ri (1lirin), the endpoints from the ith question.

Output Specification

Output q lines. In the ith line output the answer to the ith question.

Constraints

SubtaskPointsConstraints
1201n,q1000
2401n,q50000
350No additional constraints.

Sample Input 1

Copy
7 6
3 2 3 1 1 4 7
3 4
1 7
1 6
4 5
1 2
5 7

Sample Output 1

Copy
1
3
3
1
2
2

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