【13_263】Ugly Number

简单题

Ugly Number

My Submissions

Question

Total Accepted: 32635 Total Submissions: 94009 Difficulty: Easy

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.

Discuss中总有惊喜：

Java：

 for (int i=2; i<6 && num>0; i++)
     while (num % i == 0)
         num /= i;
 return num == 1;

Python：

 for p in 2, 3, 5:
     while num % p == 0 < num:
         num /= p
 return num == 1

C++：（其中&&之后的num怎么理解？）

 for (int i=; i< && num; i++)
     while (num % i == )
         num /= i;
 return num == ;

自己的：

C++：

 class Solution {
 public:
     bool isUgly(int num) {
         if (num <= )
             return false;
         if (num == )
             return true;

         while (num != )    {
             if (num %  == )   {
                 num = num / ;
             }
             else if (num %  == )  {
                 num = num / ;
             }
             else if (num %  == )  {
                 num = num / ;
             }
             else{
                 return false;
             }
         }
         return true;
     }
 };