Problem:
Score : 600 points

Problem Statement

We have N colored balls arranged in a row from left to right; the color of the i-th ball from the left is c_i.

You are given Q queries. The i-th query is as follows: how many different colors do the l_i-th through r_i-th balls from the left have?

Constraints

1\leq N,Q \leq 5 \times 10^5

1\leq c_i \leq N

1\leq l_i \leq r_i \leq N

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N Q
c_1 c_2 \cdots c_N
l_1 r_1
l_2 r_2
:
l_Q r_Q

Output

Print Q lines. The i-th line should contain the response to the i-th query.

Sample Input 1

4 3
1 2 1 3
1 3
2 4
3 3

Sample Output 1

2
3
1

The 1-st, 2-nd, and 3-rd balls from the left have the colors 1, 2, and 1 - two different colors.

The 2-st, 3-rd, and 4-th balls from the left have the colors 2, 1, and 3 - three different colors.

The 3-rd ball from the left has the color 1 - just one color.

Sample Input 2

10 10
2 5 6 5 2 1 7 9 7 2
5 5
2 4
6 7
2 2
7 8
7 9
1 8
6 9
8 10
6 8

Sample Output 2

1
2
2
1
2
2
6
3
3
3

Solution in C++ (Clang 10.0.0) (judge verdict: Time Limit Exceeded)

#include <iostream>
#include <vector>
using namespace std;

int main()
{
    uint32_t n, q;
    cin>>n>>q;
    vector<uint32_t> balls;
    uint32_t ball;
    for(uint32_t i{0}; i!=n; ++i)
    {
        cin>>ball;
        balls.push_back(ball);
    }
    uint32_t tot = 0;
    vector<pair<uint32_t, uint32_t>> queries;
    pair<int, int> query;
    for(uint32_t i{0}; i!=q; ++i)
    {
        cin>>query.first>>query.second;
        queries.push_back(query);
    }
    
    for(pair<uint32_t, uint32_t> query : queries)
    {
        for(uint32_t k{1}; k!=n+1; ++k)
        {
            for(uint32_t j{query.first-1}; j!=query.second; ++j)
            {
                if(k==balls[j])
                {
                    ++tot;
                    break;
                }
            }
        }
        cout<<tot<<"\n";
        tot = 0;
    }
}