LeetCode——Ugly Number

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;

    }
}