(easy)LeetCode 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.

代码如下：

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

　　运行结果：