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.Linq;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<int> input = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToList();
        int n = input[0];
        int a = input[1];
        int b = input[2];
        
        int output = Enumerable.Range(1, n)
            .Where(x => a <= DigitsSum(x) && DigitsSum(x) <= b)
            .Sum();

        Console.WriteLine(output);
    }

    static int DigitsSum(int num) =>
        num.ToString().ToCharArray().Select(c => int.Parse(c.ToString())).Sum();
}