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::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::iter::FromIterator;
#[allow(unused_imports)]
use std::io::{stdin, stdout, BufWriter, Write};
mod util {
    use std::io::stdin;
    use std::str::FromStr;
    use std::fmt::Debug;
    #[allow(dead_code)]
    pub fn line() -> String {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().to_string()
    }
    #[allow(dead_code)]
    pub fn gets<T: FromStr>() -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|t| t.parse().unwrap())
            .collect()
    }
}
#[allow(unused_macros)]
macro_rules ! get { ( $ t : ty ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . trim ( ) . parse ::<$ t > ( ) . unwrap ( ) } } ; ( $ ( $ t : ty ) ,* ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; let mut iter = line . split_whitespace ( ) ; ( $ ( iter . next ( ) . unwrap ( ) . parse ::<$ t > ( ) . unwrap ( ) , ) * ) } } ; ( $ t : ty ; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ ( $ t : ty ) ,*; $ n : expr ) => { ( 0 ..$ n ) . map ( | _ | get ! ( $ ( $ t ) ,* ) ) . collect ::< Vec < _ >> ( ) } ; ( $ t : ty ;; ) => { { let mut line : String = String :: new ( ) ; stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; line . split_whitespace ( ) . map ( | t | t . parse ::<$ t > ( ) . unwrap ( ) ) . collect ::< Vec < _ >> ( ) } } ; }
#[allow(unused_macros)]
macro_rules ! debug { ( $ ( $ a : expr ) ,* ) => { println ! ( concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) ; } }

#[allow(dead_code)]
/// Lazy Segment Tree
pub struct SEG<T: SEGimpl> {
    n: usize,
    buf: Vec<T::Elem>,
    zero: T::Elem,
    phantom: std::marker::PhantomData<T>,
}
impl<T: SEGimpl> SEG<T> {
    #[allow(dead_code)]
    pub fn new(n: usize, zero: T::Elem) -> SEG<T> {
        let n = (1..).map(|i| 1 << i).find(|&x| x >= n).unwrap();
        SEG {
            n,
            buf: vec![zero.clone(); 2 * n],
            zero,
            phantom: std::marker::PhantomData,
        }
    }
    #[allow(dead_code)]
    fn eval(&mut self, k: usize, l: usize, r: usize) {
        if r - l > 1 {
            let (l, r) = self.buf.split_at_mut(2 * k + 1);
            let (c1, c2) = r.split_at_mut(1);
            T::eval(&mut l[k], Some((&mut c1[0], &mut c2[0])));
        } else {
            T::eval(&mut self.buf[k], None);
        }
    }
    #[allow(dead_code)]
    fn update(&mut self, i: usize, x: T::Elem) {
        let mut k = i + self.n - 1;
        self.buf[k] = x;
        self.eval(k, i, i + 1);
        while k > 0 {
            k = (k - 1) / 2;
            let (l, r) = self.buf.split_at_mut(2 * k + 1);
            let (c1, c2) = r.split_at_mut(1);
            T::reduce(&mut l[k], &c1[0], &c2[0]);
        }
    }
    #[allow(dead_code)]
    fn get(&mut self, i: usize) -> Option<T::R> {
        self.query(i, i + 1)
    }
    #[allow(dead_code)]
    fn r(&mut self, x: &T::A, a: usize, b: usize, k: usize, l: usize, r: usize) {
        self.eval(k, l, r);
        if r <= a || b <= l {
            return;
        }
        if a <= l && r <= b {
            T::range(x, &mut self.buf[k], l, r);
            self.eval(k, l, r);
            return;
        }
        self.r(x, a, b, 2 * k + 1, l, (l + r) / 2);
        self.r(x, a, b, 2 * k + 2, (l + r) / 2, r);
        let (l, r) = self.buf.split_at_mut(2 * k + 1);
        let (c1, c2) = r.split_at_mut(1);
        T::reduce(&mut l[k], &c1[0], &c2[0]);
    }
    #[allow(dead_code)]
    pub fn range_add(&mut self, x: &T::A, a: usize, b: usize) {
        let n = self.n;
        self.r(x, a, b, 0, 0, n);
    }
    #[allow(dead_code)]
    pub fn add(&mut self, x: &T::A, i: usize) {
        self.range_add(x, i, i + 1);
    }
    #[allow(dead_code)]
    fn q(&mut self, a: usize, b: usize, k: usize, l: usize, r: usize) -> Option<T::Elem> {
        self.eval(k, l, r);
        if r <= a || b <= l {
            return None;
        }
        if a <= l && r <= b {
            Some(self.buf[k].clone())
        } else {
            let vl = self.q(a, b, k * 2 + 1, l, (l + r) / 2);
            let vr = self.q(a, b, k * 2 + 2, (l + r) / 2, r);
            match (vl, vr) {
                (Some(l), Some(r)) => {
                    let mut res = self.zero.clone();
                    T::reduce(&mut res, &l, &r);
                    Some(res)
                }
                (Some(l), None) => Some(l),
                (None, Some(r)) => Some(r),
                _ => None,
            }
        }
    }
    #[allow(dead_code)]
    pub fn query(&mut self, a: usize, b: usize) -> Option<T::R> {
        let n = self.n;
        self.q(a, b, 0, 0, n).map(T::to_result)
    }
}
pub trait SEGimpl {
    type Elem: Clone;
    type A;
    type R;
    fn eval(parent: &mut Self::Elem, children: Option<(&mut Self::Elem, &mut Self::Elem)>);
    fn range(x: &Self::A, elem: &mut Self::Elem, l: usize, r: usize);
    fn reduce(parent: &mut Self::Elem, c1: &Self::Elem, c2: &Self::Elem);
    fn to_result(elem: Self::Elem) -> Self::R;
}

struct SUM;
impl SEGimpl for SUM {
    type Elem = u64;
    type A = u64;
    type R = u64;
    #[allow(unused_variables)]
    fn eval(parent: &mut Self::Elem, children: Option<(&mut Self::Elem, &mut Self::Elem)>) {}
    #[allow(unused_variables)]
    fn range(x: &Self::A, elem: &mut Self::Elem, l: usize, r: usize) {
        *elem += *x;
    }
    fn reduce(parent: &mut Self::Elem, c1: &Self::Elem, c2: &Self::Elem) {
        *parent = *c1 + *c2;
    }
    fn to_result(elem: Self::Elem) -> Self::R {
        elem
    }
}

fn main() {
    let (n, q) = get!(usize, usize);

    let mut seg: SEG<SUM> = SEG::new(n, 0);

    for _ in 0..q {
        let (com, x, y) = get!(usize, usize, usize);

        if com == 0 {
            seg.add(&(y as u64), x - 1);
        } else {
            println!("{}", seg.query(x - 1, y).unwrap());
        }
    }
}