263. Ugly Number 丑数

https://leetcode.com/problems/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.

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;
    }
};