leetcode-Ugly Number

2017-3-8来源:ASP.NET技巧人气:2370

Question:

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.

Solution:

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

总结:

注意while判断条件是num!=1,而不是 num != 0