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++14 (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;

#define fs first
#define sc second
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define pb emplace_back

using pii = pair<int, int>;
using vi = vector<int>;
using lint = long long;

const int inf = 1001001001;
const lint linf = 1001001001001001001ll;
const int mod = 1e9 + 7;
const int dx[]{0, 1, 0, -1, -1, -1, 1, 1}, dy[]{1, 0, -1, 0, -1, 1, -1, 1};

template<typename T> inline bool chmin(T &a, T b) { if (a > b) { a = b; } return a > b; }
template<typename T> inline bool chmax(T &a, T b) { if (a < b) { a = b; } return a < b; }
template<typename T> inline void print(const T &x, string s = "\n") { cout << x << s; }
template<typename T> inline void print(const vector<T> &v, string s = " ") 
{ rep(i, v.size()) cout << v[i] << (i + 1 == v.size() ? "\n" : s); }
inline bool inside(int y, int x, int H, int W) { return 0 <= y && y < H && 0 <= x && x < W; }
inline lint in() { lint x; std::cin>>x; return x; }
/*
#include <bits/stdc++.h>
using namespace std;
 */
struct BIT {
	vector<int> v;
	int n;

	BIT() { init(); }
	BIT(int size) :n(size){ init(); }

	void init() {
		v.clear();
		v.resize(n + 1, 0);
	}

	int sum(int i, int idx = 1) {
//		idx--; idx *= -1; i += idx;
		int ret = 0;
		while (i) {
			ret += v[i];
			i -= i & -i;
		}
		return ret;
	}

	void add(int i, int x, int idx = 1) {
//		idx--; idx *= -1; i += idx;
		while (i <= n) {
			v[i] += x;
			i += i & -i;
		}
	}
};

int main() {
	int n = in(), q = in();
	BIT bit(n);

	rep(_, q) {
		int a, b, c;
		scanf("%d %d %d", &a, &b, &c);
		if (a)
			printf("%d\n", bit.sum(c) - bit.sum(b - 1));
		else 
			bit.add(b, c);
	}
}