263. Ugly Number

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.

Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

 1 public class Solution {
 2     public boolean isUgly(int num) {
 3         if(num < 1 ) return false;
 4         while(num%2 == 0) num /= 2;
 5         while(num%3 == 0) num /= 3;
 6         while(num%5 == 0) num /= 5;
 7         if(num == 1) return true;
 8         return false;
 9     }
10 }

263. Ugly Number

原文：http://www.cnblogs.com/guoguolan/p/5396262.html