leetcode刷题，总结，记录，备忘 263

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.

Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

其实做通过之后的题目都觉得不是很难了，，一个数如果不能被2， 3， 5整除，就是ugly number，除非一直被那3个数的其中某个数，整除至1。这就是解题的中心思想，上代码。

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

最后别忘，负数和0的情况，我有几次提交没过就是因为这些。。