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;

typedef int64_t i64;
typedef uint64_t ui64;

const int inf=1073741823;
const i64 llinf=4611686018427387903LL;

class bitree{
public:
    i64 *node;
    int nd;
    void make(int n){
        nd=n;
        node=new i64[nd]{};
    }
    void update(int k,i64 x){
        if(k>=nd) return;
        node[k]+=x;
        update(k+(~k&-(~k)),x);
    }
    i64 query(int a,int b){
        i64 c1=0,c2=0;
        func(a-1,c1);
        func(b-1,c2);
        return c2-c1;
    }
    void func(int k,i64 &c){
        if(k<0) return;
        c+=node[k];
        func(k-(~k&-(~k)),c);
    }
};

int main(void){
    int n;
    scanf("%i",&n);
    bitree bit;
    bit.make(n);
    int q;
    scanf("%i",&q);
    int c,p,s,t;
    i64 x;
    for(int i=0;i<q;i++){
        scanf("%i",&c);
        if(c==0){
            scanf("%i%lli",&p,&x);
            p--;
            bit.update(p,x);
        }
        if(c==1){
            scanf("%i%i",&s,&t);
            s--;
            t--;
            printf("%lli\n",bit.query(s,t+1));
        }
    }
    return 0;
}