Leetcode 263 Ugly Number

Problem:

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

Ugly numbers is positive numbers whose prime factors only include 2, 3, 5 . For example, was ugly while was not 6, 8 14 ugly since it includes another prime factor 7 .

Note that's 1 typically treated as an ugly number.

Summary:

Determine if a number is ugly number, which is only 2, 3, 5 of the mass factor.

Analysis:

The method of judging is to divide continuously by 2, 3, 5, see whether the final can get 1. The following two methods are similar.

1 classSolution {2  Public:3     BOOLisugly (intnum) {4         if(Num <=0)return false;5         6          while(num! =1) {7             if(num%2==0) Num/=2;8             Else if(num%3==0) Num/=3;9             Else if(num%5==0) Num/=5;Ten             Else return false; One         } A          -         return true; -     } the};

1 classSolution {2  Public:3     BOOLisugly (intnum) {4         if(Num <=0)return false;5         6          while(Num >=2&& num%2==0) Num/=2;7          while(Num >=3&& num%3==0) Num/=3;8          while(Num >=5&& num%5==0) Num/=5;9         Ten         returnnum = =1; One     } A};

Leetcode 263 Ugly Number