Quick Sort

## How Quick Sort Works

Quick Sort is a divide-and-conquer algorithm. It selects a 'pivot' element and partitions the array around the pivot, then recursively sorts the sub-arrays.

### Algorithm Steps:
1. Choose a pivot element (often the last element)
2. Partition: Rearrange so elements < pivot are left, > pivot are right
3. Pivot is now in its final position
4. Recursively apply to left and right sub-arrays
5. Base case: Arrays of size 0 or 1 are sorted

### Key Characteristics:
- **In-place**: Can be implemented with O(log n) extra space
- **Not Stable**: May change relative order of equal elements
- **Very Fast**: Average case O(n log n), often faster in practice