Quick Sort
Domain: Algorithms
🎯 Motivation
Pick a pivot, partition into elements smaller and larger than the pivot, then recursively sort each partition. Fast in practice, O(n log n) average.
📋 Concrete Example
Sort [5, 3, 8, 1, 4] with pivot 5: partition into [3, 1, 4] and [8], pivot in middle. Recursively sort [3, 1, 4] -> [1, 3, 4]. Result: [1, 3, 4, 5, 8].
🔗 Analogy
Splitting a class into two groups: shorter than the teacher and taller than the teacher. Then each group splits again by a new ‘pivot student’. Eventually everyone is in order.