Binary Search: Not Just for Sorted Arrays
Reframes binary search as a general search-space reduction technique rather than a sorted-array lookup trick. Covers the classic template and the two bugs that break it, then extends the idea to 'search on the answer' problems like Koko Eating Bananas and Split Array Largest Sum, and to rotated sorted arrays. Works through six real interview problems with Python solutions, explains how to recognize a hidden binary search from monotonicity, and shows why the same 15-line template solves problems that look nothing like array lookup.