# 1009. Complement of Base 10 Integer

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

## Description

The **complement** of an integer is the integer you get when you flip all the `0`'s to `1`'s and all the `1`'s to `0`'s in its binary representation.

* For example, The integer `5` is `"101"` in binary and its **complement** is `"010"` which is the integer `2`.

Given an integer `n`, return *its complement*.

**Example 1:**

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

**Example 2:**

```
**Input:** n = 7
**Output:** 0
**Explanation:** 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.
```

**Example 3:**

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

**Constraints:**

* `0 <= n < 109`

**Note:** This question is the same as 476: <https://leetcode.com/problems/number-complement/>

## ac

```java
```
