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 OCaml (4.02.3) (judge verdict: Accepted)

let () =
  let n,a,b = Scanf.scanf "%d %d %d " (fun a b c -> a,b,c) in

  let res = ref 0 in
  for i=1 to n do
    let cs = i |> string_of_int |> Batteries.String.to_list |> List.map (fun x -> int_of_char x - 48) in
    let sum = List.fold_left (+) 0 cs in
    if sum >= a && sum <= b then res := !res + i
  done;

  Printf.printf "%d\n" !res