QuickSort, MergeSort, HeapSort, and beyond — understand time/space trade-offs and when each shines.
Five passes over the same idea, each from a different angle. Do them in order, or jump to whichever you need.
Sorting is the most studied family of algorithms. Comparison sorts (quicksort, mergesort, heapsort) have an O(n log n) lower bound. Non-comparison sorts (counting, radix, bucket) beat this for constrained inputs. Stability, in-place operation, cache friendliness, and parallelizability all matter in practice.
