[백준] 1676 - 팩토리얼 0의 개수

#include <cstdio>
 
int main() {
    int N, two = 0, five = 0;
    scanf("%d", &N);
    for (int i = 2; i <= N; i++)
    {
        int num = i;
        while (true) {
            if (num % 2 == 0) {
                num /= 2;
                two++;
            }
            else if (num % 5 == 0) {
                num /= 5;
                five++;
            }
            else
                break;
        }
    }
    printf("%d\n", two > five ? five : two);
}