LeetCode 263. Ugly Number

问题描述：

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.

丑数，因子只有2,3,5的数。

AC代码：

bool isUgly(int num)     {        if(num <  1)            return false;        if(num == 1)            return true;        while(num != 1)        {            if(num % 2 == 0)                num = num/2;            else if(num % 3 == 0)                num = num/3;            else if(num % 5 == 0)                num = num/5;            else                 return false;        }        return true;    }