Advanced Topic 37 of 51 Algorithms
A* Search
Heuristic-guided shortest path search.
How it works
A* expands nodes by f = g + h, where g is cost so far and h a heuristic estimate to the goal. With an admissible (never overestimating) heuristic it finds optimal paths while exploring fewer nodes than Dijkstra.
Where it is used
Game pathfinding, robotics, puzzles.
Common pitfall
An overestimating heuristic gives suboptimal paths; poor heuristics degrade to Dijkstra.
Where it fits in the course
A* Search is topic 37 of 51 in Algorithms, rated Advanced. It follows Floyd-Warshall Algorithm. The next topic is Minimum Spanning Tree.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Algorithms quiz.
- Explore the Graph Traversal visualizer: BFS, DFS and Dijkstra on a weighted graph.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Algorithms quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is A* Search?
Heuristic-guided shortest path search. It belongs to Algorithms and is an advanced-level topic.
Where do people use A* Search?
Game pathfinding, robotics, puzzles.
What is the most common mistake with A* Search?
An overestimating heuristic gives suboptimal paths; poor heuristics degrade to Dijkstra.
What should I learn before this topic?
Start with Floyd-Warshall Algorithm, the topic just before it in Algorithms.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Algorithms quiz. You can also explore Graph Traversal in the Visual Lab.
Is A* Search hard to learn?
It is an Advanced topic. Expect to read the explanation more than once and to connect it with earlier topics. Working through a small example by hand helps most.
How long does it take to learn A* Search?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to A* Search?
Floyd-Warshall Algorithm, Minimum Spanning Tree, Bellman-Ford Algorithm are closely connected. The full list is in the related topics section of this page.
What should I study after A* Search?
Continue with Minimum Spanning Tree, the next topic in Algorithms.
Related topics
- Floyd-Warshall Algorithm (Algorithms)
- Minimum Spanning Tree (Algorithms)
- Bellman-Ford Algorithm (Algorithms)
- Kruskal's Algorithm (Algorithms)
- Search Engines (Emerging & Frontier Topics)
- Binary Search Trees (Data Structures)
- Search Algorithms in AI (AI & Machine Learning)