Day 26 — Divide & Conquer

What you’ll learn here

• The split → recurse → combine template
• Classics: merge sort, quicksort, fast exponentiation, Karatsuba multiplication, closest pair of points
• The Master Theorem for analyzing divide-and-conquer recurrences
• When divide & conquer beats iteration, and when it just adds overhead

We already used divide-and-conquer in Pow(x, n) and you’ll have seen it in merge sort. This chapter pulls the pattern out and names it.