Problem:
Score : 100 points

Problem Statement

You are given an array a_0, a_1, ..., a_{N-1} of length N. Process Q queries of the following types.

0 p x: a_p \gets a_p + x

1 l r: Print \sum_{i = l}^{r - 1}{a_i}.

Constraints

1 \leq N, Q \leq 500,000

0 \leq a_i, x \leq 10^9

0 \leq p < N

0 \leq l_i < r_i \leq N

All values in Input are integer.

Input

Input is given from Standard Input in the following format:

N Q
a_0 a_1 ... a_{N - 1}
\textrm{Query}_0
\textrm{Query}_1
:
\textrm{Query}_{Q - 1}

Output

For each query of the latter type, print the answer.

Sample Input 1

5 5
1 2 3 4 5
1 0 5
1 2 4
0 3 10
1 0 5
1 0 3

Sample Output 1

15
7
25
6

Solution in C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Linq;
using CompLib.Collections;
using CompLib.Util;

public class Program
{

    public void Solve()
    {
        var sc = new Scanner();
        int n = sc.NextInt();

        int q = sc.NextInt();
        int[] a = sc.IntArray();

        FenwickTree ft = new FenwickTree(n);
        for (int i = 0; i < n; i++)
        {
            ft.Add(i, a[i]);
        }

        Console.SetOut(new System.IO.StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        for (int i = 0; i < q; i++)
        {
            int t = sc.NextInt();
            if (t == 0)
            {
                ft.Add(sc.NextInt(), sc.NextInt());
            }
            else
            {
                Console.WriteLine(ft.Sum(sc.NextInt(), sc.NextInt()));
            }
        }
        Console.Out.Flush();
    }

    public static void Main(string[] args) => new Program().Solve();
    // public static void Main(string[] args) => new Thread(new Program().Solve, 1 << 27).Start();
}

namespace CompLib.Collections
{
    using Num = System.Int64;

    public class FenwickTree
    {
        private readonly Num[] _array;
        public readonly int Count;

        public FenwickTree(int size)
        {
            _array = new Num[size + 1];
            Count = size;
        }

        /// <summary>
        /// A[i]にnを加算
        /// </summary>
        /// <param name="i"></param>
        /// <param name="n"></param>
        public void Add(int i, Num n)
        {
            i++;
            for (; i <= Count; i += i & -i)
            {
                _array[i] += n;
            }
        }

        /// <summary>
        /// [0,r)の和を求める
        /// </summary>
        /// <param name="r"></param>
        /// <returns></returns>
        public Num Sum(int r)
        {
            Num result = 0;
            for (; r > 0; r -= r & -r)
            {
                result += _array[r];
            }

            return result;
        }

        /// <summary>
        /// [0,i)の和がw以上になるi
        /// </summary>
        /// <param name="w"></param>
        /// <returns></returns>
        public int LowerBound(Num w)
        {
            if (w <= 0) return 0;
            int x = 0;
            int k = 1;
            while (k * 2 < Count) k *= 2;
            for (; k > 0; k /= 2)
            {
                if (x + k < Count && _array[x + k] < w)
                {
                    w -= _array[x + k];
                    x += k;
                }
            }
            return x + 1;
        }

        // [l,r)の和を求める
        public Num Sum(int l, int r) => Sum(r) - Sum(l);
    }
}

namespace CompLib.Util
{
    using System;
    using System.Linq;

    class Scanner
    {
        private string[] _line;
        private int _index;
        private const char Separator = ' ';

        public Scanner()
        {
            _line = new string[0];
            _index = 0;
        }

        public string Next()
        {
            if (_index >= _line.Length)
            {
                string s;
                do
                {
                    s = Console.ReadLine();
                } while (s.Length == 0);

                _line = s.Split(Separator);
                _index = 0;
            }

            return _line[_index++];
        }

        public string ReadLine()
        {
            _index = _line.Length;
            return Console.ReadLine();
        }

        public int NextInt() => int.Parse(Next());
        public long NextLong() => long.Parse(Next());
        public double NextDouble() => double.Parse(Next());
        public decimal NextDecimal() => decimal.Parse(Next());
        public char NextChar() => Next()[0];
        public char[] NextCharArray() => Next().ToCharArray();

        public string[] Array()
        {
            string s = Console.ReadLine();
            _line = s.Length == 0 ? new string[0] : s.Split(Separator);
            _index = _line.Length;
            return _line;
        }

        public int[] IntArray() => Array().Select(int.Parse).ToArray();
        public long[] LongArray() => Array().Select(long.Parse).ToArray();
        public double[] DoubleArray() => Array().Select(double.Parse).ToArray();
        public decimal[] DecimalArray() => Array().Select(decimal.Parse).ToArray();
    }
}