Description：
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.
寻找丑数：
public class Solution { public boolean isUgly(int num) { if(num <= 0) { return false; } while(num % 2 == 0) { num /= 2; } while(num % 3 == 0) { num /= 3; } while(num % 5 == 0) { num /= 5; } return num == 1; } }
原文：http://www.cnblogs.com/wxisme/p/4841292.html