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 C (GCC 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
int sum(int K){
  int a=0;
for(;K>0;K=K/10){
  a=a+K%10;
  }
  return a;
}
int main()
{
  int N,A,B,answer=0;
  scanf("%d %d %d",&N,&A,&B);
  for(;N>0;N=N-1){
    if(A<=sum(N)&&sum(N)<=B){
      answer=answer+N;
    }
  }
  printf("%d\n",answer);
  return 0;
}