# 1009. Complement of Base 10 Integer

**<font color=red>难度: Easy</font>**

## 刷题内容

> 原题连接

* https://leetcode.com/problems/complement-of-base-10-integer/

> 内容描述

```
Every non-negative integer N has a binary representation.  For example, 5 can be represented as "101" in binary, 11 as "1011" in binary, and so on.  Note that except for N = 0, there are no leading zeroes in any binary representation.

The complement of a binary representation is the number in binary you get when changing every 1 to a 0 and 0 to a 1.  For example, the complement of "101" in binary is "010" in binary.

For a given number N in base-10, return the complement of it's binary representation as a base-10 integer.

 

Example 1:

Input: 5
Output: 2
Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10.
Example 2:

Input: 7
Output: 0
Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.
Example 3:

Input: 10
Output: 5
Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.
 

Note:

0 <= N < 10^9
```

## 解题方案

> 思路 1
******- 时间复杂度: O(lgN)******- 空间复杂度: O(lgN)******

一行

```python
class Solution:
    def bitwiseComplement(self, N: int) -> int:
        return int(''.join(['0' if i == '1' else '1' for i in bin(N)[2:]]), 2)
```
