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 (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main()
{
	long int s;
	int i, N, Q, c[500000], l[500000], r[500000], m, k, ans[500000];
	scanf("%d%d", &N, &Q);
	c[N + 1] = '\0';
	for (i = 0; i < N; i++) {
		scanf("%d", &c[i]);
	}
	for (s = 0; s < 500000; s++) {
		ans[s] = 0;
	}
	for (i = 0; i <= Q; i++) {
		scanf("%d%d", &l[i], &r[i]);
	}
	for (i = 0; i <= Q; i++) {
		for (m = l[i]; m <= r[i]; m++) {
			for (k = l[i]; k <= r[i]; k++) {
				if (c[k] != c[m]) {
					ans[Q]++;
				}
			}
			break;
		}
	}
	for (i = 0; i <= Q; i++) {
		printf("%d\n", ans[Q]);
	}
}