Add Quick Sort algorithm
Closes #17 (closed)
Add Quick Sort algorithm with median-of-three optimization
Changes
- Implemented Quick Sort algorithm in sort.py
- Added median-of-three pivot selection to improve performance on sorted/reverse sorted arrays
- Registered algorithm in test suite with full metadata
- Updated README documentation
- Added to demo program
Testing
All 50 tests pass including:
- Correctness tests on various input patterns
- Input immutability verification
- Performance test on 1000-element reversed array
Complexity
- Time: O(n log n) average, O(n²) worst case
- Space: O(log n) due to recursion stack
- Stable: No