末尾0的個數

題目描述

輸入一個正整數，求n！末尾有多少個0?比如n = 10; n! = 3628800 ,所以答案為2

package javaPractice;

import java.util.*;

public class CountZero {
	public static void main(String[] args) {
		CountZero cz = new CountZero();
		Scanner s = new Scanner(System.in);
		int n = s.nextInt();
		System.out.println(n+"d的階乘中尾部零的個數為："+cz.countFive(n));
		
	}
	public int countFive(int n) {
		int count = 0;
		if(n<5) {
			return count;
		}
		else {
			return n/5 + countFive(n/5);
		}
	}
}