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++11 (judge verdict: Runtime Error)

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

struct query {
	int x;
	int y;
	bool operator < (const query & r) const {
		return this->x < r.x;
	}
};

int dat[100001] = {};
vector<query> update_list;
int min_updated = 100001;

int n;

inline void add(int x, int y) {
	min_updated = min(min_updated, x);
	update_list.push_back(query{ x, y });
}

inline void update(int x) {
	if (x < min_updated)
		return;
	min_updated = 100001;
	
	sort(begin(update_list), end(update_list));
	int sum = 0;
	int sum_index = 1;
	for (query it : update_list) {
		while (sum_index < it.x) {
			dat[sum_index] += sum;
			sum_index = sum_index + sum_index&(-sum_index);
		}
		while (sum_index > it.x) {
			dat[it.x] += it.y;
			it.x += it.x & (-it.x);
		}
		//sum_index == it.x
		sum += it.y;
	}
	update_list.clear();
	while (sum_index <= n) {
		dat[sum_index] += sum;
		sum_index += sum_index&(-sum_index);
	}
}

inline int sum(int x) {
	int s = 0;
	while (x > 0) {
		s += dat[x];
		x -= x&-x;
	}
	return s;
}

inline int getSum(int x, int y) {
	update(y);
	return sum(y) - sum(x - 1);
}

int main() {
	int q;
	cin >> n >> q;
	for (int i = 0; i < q; ++i) {
		int c, x, y;
		cin >> c >> x >> y;
		if (c == 0)
			add(x, y);
		else
			cout << getSum(x, y) << endl;
	}
}