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>
int N,B[100010]={0};
void bset(int n){for(N=1;N<n;N+=2);}
void badd(int i,int n){for(;i<=N;i+=i&-i)B[i]+=n;}
int  bsum(int i){
  int s=0;
  for(;i;i-=i&-i)s+=B[i];
  return s;
}		   
int main(){
  int n,m,a,b,c;
  scanf("%d %d",&N,&m);
  //bset(n);
  while(m--){
    scanf("%d %d %d",&a,&b,&c);
    a?printf("%d\n",bsum(c)-bsum(b-1)):badd(b,c);
  }    
  return 0;
}