Fibonacci Heap — Priority Queue Operations

A Fibonacci heap achieves amortized O(1) insert/decrease-key and O(log n) extract-min, crucial for optimal Dijkstra's and Prim's algorithms.

Fibonacci heaps (Fredman & Tarjan, 1987) use a lazy forest of heap-ordered trees. Amortized complexity: insert O(1), find-min O(1), extract-min O(log n), decrease-key O(1), union O(1). The name comes from the degree bound: degree ≤ log_φ(n), related to Fibonacci numbers.