263. Ugly Number

题目：

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.
思路：
题目较为简单，循环判断即可。

代码：

public class Solution {
public boolean isUgly(int num) {
if(num == 1){return true;}
if(num < 1){return false;}

while(num%2 == 0){
num /= 2;
}
while(num%3 == 0){
num /= 3;
}
while(num%5 == 0){
num /= 5;
}

if(num == 1){
return true;
}else{
return false;
}
}
}