LeetCode263——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.

实现：

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);

        else if (num % 3 == 0) return isUgly(num/3);

        else if (num % 5 == 0) return isUgly(num/5);

        return false;

    }

};