题解 | #数位五五#

#include <stdio.h>

int isPass(int n) {
    return n % 5 == 0;
}

int digit(int n) {
    int total = 0;
    while(n > 0) {
        total += n % 10;
        n /= 10;
    }
    return total;
    
}

int main() {
    int a, b, d, n = 0;
    scanf("%d%d", &a, &b);
    for(int i = a; i <= b; i++) {
        if(isPass(digit(i))) {
            n++;
        }
        
    }
    
    printf("%d\n", n);
    
    return 0;
}