Problem:
Range Sum Query

Write a program which manipulates a sequence A = {a1, a2, . . . , an} with the following operations:

add(i, x): add x to ai.

getSum(s, t): print the sum of as, as+1,...,at.

Note that the initial values of ai (i = 1, 2, . . . , n) are 0.

Input

n q
com1 x1 y1
com2 x2 y2
...
comq xq yq

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, q queries are given where com represents the type of queries. '0' denotes add(xi, yi) and '1' denotes getSum(xi, yi).

Output

For each getSum operation, print the sum in a line.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

If comi is 0, then 1 ≤ xi ≤ n, 0 ≤ yi ≤ 1000.

If comi is 1, then 1 ≤ xi ≤ n, 1 ≤ yi ≤ n.

Sample Input 1

3 5
0 1 1
0 2 2
0 3 3
1 1 2
1 2 2

Sample Output 1

3
2

Solution in C (judge verdict: Accepted)

#include<stdio.h>
#define rep(i,n)for(i=0;i<n;i++)

int bit[100001], n, q, i;
int com, x, y; 
int sum(int i) {
	int s = 0;
	while (i > 0) {
		s += bit[i];
		i -= i&-i;
	}
	return s;
}
void add(int i, int x) {
	while (i <= n) {
		bit[i] += x;
		i += i&-i;
	}
}
int main() {
	scanf("%d%d", &n, &q);
	rep(i, q) {
		scanf("%d%d%d", &com, &x, &y);
		if (com) printf("%d\n", sum(y) - sum(x - 1));
		else add(x, y);
	}
	return 0;
}