263. 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.

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代码：

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