FREQUENT - Frequent values

You are given a sequence of n integers a1, a2 ... an in non-decreasing order. In addition to that, you are given several queries consisting of indices i and j (1 ≤ i ≤ j ≤ n). For each query, determine the most frequent value among the integers ai ... aj.

Input Specification

The input consists of several test cases. Each test case starts with a line containing two integers n and q (1 ≤ n, q ≤ 100000). The next line contains n integers a1 ... an (-100000 ≤ ai ≤ 100000, for each i ∈ {1 ... n}) separated by spaces. You can assume that for each i ∈ {1 ... n-1}: ai ≤ ai+1. The following q lines contain one query each, consisting of two integers i and j (1 ≤ i ≤ j ≤ n), which indicate the boundary indices for the query.

The last test case is followed by a line containing a single 0.

Output Specification

For each query, print one line with one integer: The number of occurrences of the most frequent value within the given range.

Sample Input

10 3
-1 -1 1 1 1 1 3 10 10 10
2 3
1 10
5 10
0

Sample Output

1
4
3

A naive algorithm may not run in time!

Added by:Adrian Kuegel
Date:2007-07-06
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:University of Ulm Local Contest 2007

hide comments
2017-05-26 22:34:16
Hurrah..!!
First problem on Segment tree,all by myself...
AC in one go... :-)
2017-03-05 00:19:17
Nice Question. AC in one go!

Last edit: 2017-03-05 00:19:48
2017-02-14 21:23:07
Yippee! Accepted with python 2.6 (PyPy)
According to this benchmark
https://blog.famzah.net/2016/02/09/cpp-vs-python-vs-perl-vs-php-performance-benchmark-2016/
python 3 (together with ruby) is 15-20 slower than c++
and thats why I couldnt break time limit
But PyPy was my savior.
0.5 secs I guess its not that bad considering that best results with c++ are about 0.1 secs

Last edit: 2017-02-15 12:32:09
2017-02-12 16:10:46
All it needs is fast i/o
2017-01-01 19:21:47
Testcases to check. http://spojtoolkit.com/history/FREQUENT
2016-12-15 19:42:06
my 100th ... :) :) :) and AC in one go with segment tree
2016-12-13 08:57:32 king
At last AC, A must do question of segment tree
2016-12-12 22:50:16 Abhishek Kainth
O(N*log(N)) precomputation using Sparse Table
O(1) per query :D
2016-11-02 00:09:30
what to do in case of a tie !!
2016-10-16 06:23:59
o.O OMG !!, this shit is solved ... :D
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