# 263.Ugly Numbers

**263.Ugly Numbers**

难度:Easy

> 编写一个程序判断给定的数是否为丑数。

丑数就是只包含质因数 2, 3, 5 的正整数。

```
示例 1:

输入: 6
输出: true
解释: 6 = 2 × 3
示例 2:

输入: 8
输出: true
解释: 8 = 2 × 2 × 2
示例 3:

输入: 14
输出: false 
解释: 14 不是丑数，因为它包含了另外一个质因数 7。
说明：

1 是丑数。
输入不会超过 32 位有符号整数的范围: [−231,  231 − 1]。
```

能整除2 3 5的话，分别整除至不能整除，看看最后是否等于1即可。

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

> 执行用时 :4 ms, 在所有 C++ 提交中击败了90.96%的用户\
> 内存消耗 :8 MB, 在所有 C++ 提交中击败了60.22%的用户


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