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 C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;




namespace contest
{

    class contest
    {


        static void Main(string[] args)
        {


            //int n = int.Parse(Console.ReadLine());
            //var input = Console.ReadLine().Split().Select(int.Parse).ToArray();

            //var num = Console.ReadLine().Split().Select(int.Parse).ToArray();



            var num = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int n = num[0];
            int q = num[1];
            var input = new int[q][];
            for(int i =0; i< q; i++)
            {
                input[i] = Console.ReadLine().Split().Select(int.Parse).ToArray();
            }

            var arr = new int[n+1];
            int len = (int)Math.Sqrt(n) + 1;
            var dicom = new int[len];

            for (int i = 0; i < q; i++)
            {
                int dir = input[i][0];
                int l = input[i][1];
                int r = input[i][2];

                int sum = 0;
                if(dir==0)
                {
                    arr[l] += r;
                    dicom[l / len] += r;
                }
                else
                {
                    
                    for(int j = l; j<= r; )
                    {
                        if(j%len==0 && j+len-1 <= r)
                        {
                            sum += dicom[j/len];
                            j += len;
                        }
                        else
                        {
                            sum += arr[j];
                            j++;
                        }
                    }
                    Console.WriteLine(sum);
                }

            }





        }


        


       


    }


}