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 JavaScript (judge verdict: Accepted)

var data = [];
function init(n) {
    for (var i = 0; i < n * 2 - 1; i++) data[i] = 0;
}
function getSum(s, t, k, l, r) {
    if (r <= s || t <= l) return 0;
    if (s <= l && r <= t) return data[k];

    var mid = Math.floor((l + r) / 2);
    var lv = getSum(s, t, k * 2 + 1, l, mid);
    var rv = getSum(s, t, k * 2 + 2, mid, r);

    return lv + rv;
}

var input = require('fs').readFileSync('/dev/stdin', 'utf8').trim();
var lines = input.split('\n');

var items = lines.shift().trim().split(' ');
var n = +items[0];
var q = +items[1];

var m = 1;
while (m < n) m *= 2;

function add(i, x) {
    i += m - 1;
    data[i] += x;
    while (i > 0) {
        i = Math.floor((i - 1) / 2);
        var c1 = data[i * 2 + 1];
        var c2 = data[i * 2 + 2];
        data[i] = c1 + c2;
    }
}

init(m);

var line;
while (line = lines.shift()) {
    var com = line.trim().split(' ').map(function(n){return +n;});
    if (com[0] == 0) {
        add(com[1] - 1, com[2]);
    } else {
        console.log(getSum(com[1] - 1, com[2], 0, 0, m));
    }
}