263. Ugly Number 丑数

​​https://leetcode.com/problems/ugly-number/​​

Write a program to check whether a given number is an ugly number.

​​2, 3, 5​​. For example, ​​6, 8​​ are ugly while ​​14​​ is not ugly since it includes another prime factor ​​7​​.​​1​​

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

class Solution {
public:
    bool 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?true:false;
    }
};