A*: Dijkstra With a Sense of Direction

A* is the pathfinding algorithm behind games, robots, and GPS — Dijkstra plus a heuristic that aims the search at the goal. This episode animates A* expanding by f = g + h and skipping nodes Dijkstra would have explored. (Graph Algos II.) • f = g + h: real cost so far plus an estimate of the cost to go • An animated run showing the heuristic steer past dead ends • The Python implementation — Dijkstra with one extra term • Admissible heuristics, and why they guarantee the optimal path • h = 0 turns A* back into Dijkstra; sharper h explores less • Where it's used: game AI, robotics, GPS routing Chapters: 0:00 Intro 0:21 f = g + h 0:47 A* run (animated) 1:41 A* in Python 2:16 The heuristic is everything 2:44 Complexity & uses 3:10 Recap — and Trie next #AStar #Pathfinding #Graphs #Algorithms #Python #GameDev #InterviewPrep