LeetCode 263. Ugly Number

原题链接在这里：https://leetcode.com/problems/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.

题解：

判断一个数是不是ugly number, 是看它能否被2, 3, 5整除即可.

AC Java:

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;
    }
}

跟上Ugly Number II.