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 Haskell (GHC 7.10.3) (judge verdict: Accepted)


digitSum n = inner n 0
  where inner 0 rv = rv
        inner m rv = let (q, r) = quotRem m 10
                     in
                       inner q (r + rv)

sums n = [ (k, digitSum k) | k <- [1 .. n]]

sums10000 = sums 10000

filterSums n a b = filter (\(_, x) -> a <= x && x <= b) $ take n sums10000

answer n a b = foldr (\(x, _) y -> x + y) 0
               $ filterSums n a b

main = interact $ (++ "\n")
       . show 
       . (\[x, y, z] -> answer x y z)
       . map read
       . take 3
       . words
       . head
       . lines