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 Rust (judge verdict: Accepted)

struct SegmentTree{
    node : Vec<i64>,
    size : usize,
}

impl SegmentTree{
    fn new(size : usize)->SegmentTree{
        let mut x:usize =1;
        while x<size{
            x*=2;
        }
        SegmentTree{
            node : vec![0;2*x-1],
            size : x,
        }
    }
    fn add(&mut self, mut k:usize,x:i64){
        k+=self.size-1;
        self.node[k]+=x;
        while k>0{
            k=(k-1)/2;
            self.node[k]+=x;
        }
    }

    fn getsum( &self,a:usize,b:usize,k:usize,l:usize,r:usize)->i64{
        if r<=a || b<=l{
            return 0;
        }
        if a<=l && r<=b{
            return self.node[k];
        }
        let lx=self.getsum(a,b,2*k+1,l,(l+r)/2);
        let rx=self.getsum(a,b,2*k+2,(l+r)/2,r);
        lx+rx
    }
    fn get_sum(&self,a:usize,b:usize)->i64{
        self.getsum(a,b,0,0,self.size)
    }
}



fn main(){
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let v:Vec<usize>=s.trim().split_whitespace()
                    .map(|e|e.parse().unwrap()).collect();
    let (n,m)=(v[0],v[1]);
    let mut sg =SegmentTree::new(n);
    for _ in 0..m {
        let mut t = String::new();
        std::io::stdin().read_line(&mut t).unwrap();
        let x:Vec<usize>=t.trim().split_whitespace()
                    .map(|e|e.parse().unwrap()).collect();
        match x[0]{
            1 => println!("{}",sg.get_sum(x[1]-1, x[2]) ),
            0 => {
                let z=x[2] as i64;
                sg.add(x[1]-1, z);

            },
            _ => println!("{}",x[0]),
        }
    }
}