题解 | #数位五五#

#include <stdio.h>

int is_five(int i);

int main() {
    int a, b;
    
    while (2 == scanf("%d %d", &a, &b))
    {
        int count = 0;
        for (int i = a; i <= b; i++)
        {
            if (is_five(i))
            {
                count++;
            }
        }
        printf("%d\n", count);
    }

    return 0;
}

int is_five(int i)
{
    int flag = 0;
    int sum = 0;
    while (i)
    {
        sum += (i % 10);
        i /= 10;
    }
    if (sum % 5 == 0)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}