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 Scala (2.11.7) (judge verdict: Accepted)

object Main extends App {

  val Array(n, a, b) = io.StdIn.readLine.split(" ").map(_.toInt)

  val ans = (1 to n).foldLeft(0)( (acc,i) => {
    val sum = (1 to 5).foldLeft((i,0))( (acc,_) => {
      (acc._1 / 10, acc._2 + (acc._1 % 10))
    })._2
    if(a <= sum && sum <= b ) acc + i else acc
  })

  println(ans)
}