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 JAVA (judge verdict: Accepted)

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        int size = scan.nextInt(), queries = scan.nextInt();
        RangeSumQuery rmq = new RangeSumQuery(size);
        for(int i = 0; i < queries; i++){
            int c = scan.nextInt(); int x = scan.nextInt(); int y = scan.nextInt();
            if(c == 0) rmq.update(x - 1, y);
            else System.out.println(rmq.rangemin(x - 1, y - 1));
        }
    }
}

class RangeSumQuery{
    int height;
    int tree[];
    RangeSumQuery(int size){
        for(height = 0; 1 << height < size; height++);
        tree = new int[1 << (height + 1)];
        for(int i = 0; i < tree.length; i++) tree[i] = 0;
    }

    private int sibling(int i){
        if(i == 0) throw new IllegalArgumentException("");
        return ((i - 1) ^ 1) + 1;
    }

    void update(int i, int x){
        i += (1 << height) - 1;
        for(; i != 0; i = (i - 1) / 2) tree[i] += x;
        tree[0] += x;
        //dump();
    }

    int rangemin(int from, int to){
        if(!(0 <= from && from <= to && to < (1 << height)))
            throw new IllegalArgumentException("");
        int depth = height, size = (to - from) + 1, r = 0;
        from += (1 << height) - 1;
        while(0 < size){
            for(; from % 2 == 1 && 2 << (height - depth) <= size; depth--, from /= 2);
            for(; size < 1 << (height - depth); depth++, from = from * 2 + 1);
            r += tree[from];
            from++;
            size -= 1 << (height - depth);
        }
        return r;
    }

    void dump(){
        int subarr[];
        for(int i = 0; i <= height; i++){
            subarr = Arrays.copyOfRange(tree, (1 << i) - 1, (1 << i + 1) - 1);
            System.out.println(Arrays.toString(subarr));
        }
    }
}