Problem:
Score : 200 points

Problem Statement

Find the sum of the integers between 1 and N (inclusive), whose sum of digits written in base 10 is between A and B (inclusive).

Constraints

1 \leq N \leq 10^4

1 \leq A \leq B \leq 36

All input values are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

Print the sum of the integers between 1 and N (inclusive), whose sum of digits written in base 10 is between A and B (inclusive).

Sample Input 1

20 2 5

Sample Output 1

84

Among the integers not greater than 20, the ones whose sums of digits are between 2 and 5, are: 2,3,4,5,11,12,13,14 and 20. We should print the sum of these, 84.

Sample Input 2

10 1 2

Sample Output 2

13

Sample Input 3

100 4 16

Sample Output 3

4554

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Text;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using static System.Console;
using static System.Math;

namespace AtCoder
{
    public class Program
    {
        public static void Main(string[] args)
        {
            new Program().Solve(new ConsoleInput(Console.In, ' '));
            Console.ReadLine();
        }

        public void Solve(ConsoleInput cin)
        {
            int size = cin.ReadInt;
            int min = cin.ReadInt;
            int max = cin.ReadInt;
            int cnt = 0;

            for (int i = 1; i <= size; i++)
            {
                string num = i.ToString();
                int sum = 0;
                do {
                    // 12345
                    sum += int.Parse(num.Substring(num.Length - 1));
                    num = num.Substring(0, num.Length - 1);
                } while (num.Length > 0) ;

                if (sum >= min && sum <= max)
                {
                    cnt += i;
                }
            }

            Console.WriteLine(cnt);
        }


    }

    public class ConsoleInput
    {
        private readonly System.IO.TextReader _stream;
        private char _separator = ' ';
        private Queue<string> inputStream;
        public ConsoleInput(System.IO.TextReader stream, char separator = ' ')
        {
            this._separator = separator;
            this._stream = stream;
            inputStream = new Queue<string>();
        }
        public string Read
        {
            get
            {
                if (inputStream.Count != 0) return inputStream.Dequeue();
                string[] tmp = _stream.ReadLine().Split(_separator);
                for (int i = 0; i < tmp.Length; ++i)
                    inputStream.Enqueue(tmp[i]);
                return inputStream.Dequeue();
            }
        }
        public string ReadLine { get { return _stream.ReadLine(); } }
        public int ReadInt { get { return int.Parse(Read); } }
        public long ReadLong { get { return long.Parse(Read); } }
        public double ReadDouble { get { return double.Parse(Read); } }
        public string[] ReadStrArray(long num) { var ret = new string[num]; for (long i = 0; i < num; ++i) ret[i] = Read; return ret; }
        public int[] ReadIntArray(long num) { var ret = new int[num]; for (long i = 0; i < num; ++i) ret[i] = ReadInt; return ret; }
        public long[] ReadLongArray(long num) { var ret = new long[num]; for (long i = 0; i < num; ++i) ret[i] = ReadLong; return ret; }
    }
}