public class Solution
extends Object
476 - Number Complement\.
Easy
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 `num`, return _its complement_.
**Example 1:**
**Input:** num = 5
**Output:** 2
**Explanation:** The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.
**Example 2:**
**Input:** num = 1
**Output:** 0
**Explanation:** The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.
**Constraints:**
* 1 <= num < 231
**Note:** This question is the same as 1009: [https://leetcode.com/problems/complement-of-base-10-integer/](https://leetcode.com/problems/complement-of-base-10-integer/)