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)

#[allow(unused_imports)]
use std::cmp::{min,max};
#[allow(unused_imports)]
use std::collections::{BTreeMap,BTreeSet};
#[allow(unused_imports)]
use std::ops::*;
#[allow(unused_imports)]
use std::collections::BinaryHeap;

#[allow(unused_macros)]
macro_rules! tf {
    ($c:expr, $t:expr, $f:expr) => {{
        if $c { $t } else { $f }
    }};
}

struct BIT<T> {
    xs: Vec<T>,
    n: usize,
}

// 0-indexed
impl<T:Add<T,Output=T>+Sub<T,Output=T>+Default+Clone+Copy> BIT<T> {
    fn new(n: usize) -> BIT<T> {
        let mut m = 1;
        while m < n {
            m *= 2;
        }
        let n = m;
        BIT::<T> {
            xs: vec![T::default(); n+1],
            n: n
        }
    }
    fn sum(&self, i: usize) -> T {
        let mut i = i + 1;
        let mut res = T::default();
        while i > 0 {
            res = res + self.xs[i];
            i = i - (1usize << i.trailing_zeros());
        }
        res
    }
    fn range_sum(&self, l: usize, r: usize) -> T {
        self.sum(r-1) - self.sum(l-1)
    }
    fn add(&mut self, i: usize, x: T) {
        let mut i = i + 1;
        while i <= self.n {
            self.xs[i] = self.xs[i] + x;
            i = i + (1usize << i.trailing_zeros())
        }
    }
}

fn main() {
    let (n,q) = {
        let xs = read_vec_i64();
        (xs[0] as usize, xs[1] as usize)
    };
    let mut bit: BIT<i64> = BIT::new(n);
    for i in 0..q {
        let (com,x,y) = {
            let xs = read_vec_i64();
            (xs[0] as usize, xs[1] as usize, xs[2] as usize)
        };
        if com == 0 {
            bit.add(x-1, y as i64);
        }
        if com == 1 {
            let res = bit.range_sum(x-1, y);
            println!("{}", res);
        }
    }
}

#[allow(dead_code)]
fn read_line() -> String {
    let mut ret = String::new();
    std::io::stdin().read_line(&mut ret).ok();
    ret.pop();
    //ret.pop();
    return ret;
}

#[allow(dead_code)]
fn read_i64() -> i64 {
    let ss = read_line();
    return ss.parse::<i64>().unwrap();
}

#[allow(dead_code)]
fn read_vec_i64() -> Vec<i64> {
    let mut res = vec![];
    let ss = read_line();
    for ts in ss.split_whitespace() {
        let x = ts.parse::<i64>().unwrap();
        res.push(x);
    }
    return res;
}

use std::fmt::Display;
#[allow(dead_code)]
fn write_vec<T: Display>(xs: &Vec<T>) {
    if xs.len() == 0 {
        println!("");
        return;
    }
    print!("{}", xs[0]);
    for i in 1..xs.len() {
        print!(" {}", xs[i]);
    }
    println!("");
}