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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
)

func sum_of_digit(n int) int {
	var sum int
	for n > 0 {
		sum += n % 10
		n /= 10
	}
	return sum
}
func main() {
	var n, a, b, sum int
	fmt.Scan(&n, &a, &b)
	for i := 1; i < n+1; i++ {
		if v := sum_of_digit(i); a <= v && v <= b {
			sum += i
		}
	}
	fmt.Println(sum)
}