leetcode-Ugly Number

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