n!末尾有多个个零

#include <stdint.h>
#include <iostream>
using namespace std;
unsigned fun(unsigned n) {
	unsigned sum5 = 0;
	int t = 0;
	for (int i = 5;i <= n;i += 5) {
		t = i;
		while (t >= 5) {
			if (0 == t % 5) {
				++sum5;
			}
			t /= 5;
		}
	}
	return sum5;
}
int fun1(int n) {
	unsigned cnt = 0;
	while (n /5 != 0) {
		cnt = cnt + n/5;
		n /= 5;
	}
	return cnt;
}
int main() {
	unsigned n;
	n = 26;
	for (int i = 0;i < 1000000;i++) {
		//fun(n);			// 0.054s
		fun1(n);			// 0.024s
	}

	return 0;
}