LeetCode -- Ugly Number - c++编程基础

题目描述：

Write a program to check whether a given number is an ugly number.

Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

Note that 1 is typically treated as an ugly number.

判断一个数是否为ugly number。

对2,3,5执行以下过程：
不断除n，直到无法整除。

最后剩余数字为1，则该数为ugly number。

实现代码：

public class Solution {
    public bool IsUgly(int num) 
    {
        if(num <= 0){
            return false;
        }
        num = Divide(num,2);
    	num = Divide(num,3);
    	num = Divide(num,5);
    	
    	return num == 1;
    }


private int Divide(int num, int a)
{
	while(num % a == 0){
		num /= a;
	}
	return num;
}


}