[leetcode]263. Ugly Number丑数

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.

丑数是一个正数且因子只包含2，3，5的数

class Solution {
public:
    bool isUgly(int num) {
        while(1)
        {
            if(num == 1)    return true;
            if(num <= 0) return false;
            
            //用%表示是否能整除，能整除且除了之后等于1则是uglynum
            if(num % 2 == 0)
            {
                num = num / 2;
                if(num == 1)    return true;
            }
            else if(num % 3 == 0)
            {
                num = num / 3;
                if(num == 1)    return true;
            }
            else if(num % 5 == 0)
            {
                num = num / 5;
                if(num == 1)    return true;
            }
            else
            {
                return false;
            }


        }
        
    }
};

void main()
{
	Solution *s = new Solution();
	bool result = s->isUgly(22);
	cout<