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 Common Lisp (SBCL 1.1.14) (judge verdict: Accepted)


(defun digit-sum (n)
  (labels ((inner (m rv)
             (cond
               ((zerop m) rv)
               (t
                (multiple-value-bind (q r) (floor m 10)
                  (inner q (+ rv r)))))))
    (inner n 0)))

(defparameter sums
  (loop for n from 0 upto 10000
        collect `(,n ,(digit-sum n))))

(defun filter-sum (n a b)
  (let ((k (if (< 10001 n)
               10001
               (1+ n))))
    (remove-if-not #'(lambda (m) (<= a m b))
                   (subseq sums 0 k)
                   :key #'cadr)))

(defun answer (n a b)
  (loop for k in (filter-sum n a b)
        sum (car k)))

(let ((n (read)) (a (read)) (b (read)))
  (format t "~a~%" (answer n a b)))