## Leetcode - Hamming Distance

https://leetcode.com/problems/hamming-distance/

The Hamming distance between two integers is the number of positions at which the corresponding bits are different.

Given two integers `x` and `y`, calculate the Hamming distance.

Note:
0 ≤ `x`, `y` < 231.

Example:

```Input: x = 1, y = 4

Output: 2

Explanation:
1   (0 0 0 1)
4   (0 1 0 0)
↑   ↑

The above arrows point to positions where the corresponding bits are different.
```

## Leetcode - Number of 1 Bits

https://leetcode.com/problems/number-of-1-bits/

Write a function that takes an unsigned integer and return the number of '1' bits it has (also known as the Hamming weight).

Example 1:

```Input: 00000000000000000000000000001011
Output: 3
Explanation: The input binary string `00000000000000000000000000001011 has a total of three '1' bits.`
```

## Leetcode - Bitwise AND of Numbers Range

https://leetcode.com/problems/bitwise-and-of-numbers-range/

Given a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND of all numbers in this range, inclusive.

Example 1:

```Input: [5,7]
Output: 4
```

Example 2:

```Input: [0,1]
Output: 0```

## Leetcode - Single Number

https://leetcode.com/problems/single-number/

Given a non-empty array of integers, every element appears twice except for one. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Example 1:

```Input: [2,2,1]
Output: 1
```