How to Solve Mazes: From Right-Hand Rule to A* (With Visuals)
2025-10-10โข12 min readโขBy Qin WenLong
StrategyGuideBFSDijkstraA*
How to Solve Mazes: From Right-Hand Rule to A* (With Visuals)
Want to solve mazes systematically? This guide covers intuitive and algorithmic approaches, explains when each works best, and offers speedrun tips.
1) Right-Hand Rule (Wall Following)
- Intuition: keep your right hand on the wall and keep moving
- Best for: simple, connected planar mazes; does not guarantee shortest path
- Limitation: can loop in mazes with cycles
Practice
- Try it in /maze; zoom in slightly and focus on consistent wall contact
2) Junction Mapping
- Mark each junction (on paper or mentally) to avoid revisiting explored branches
- Ideal for medium-complexity mazes
3) BFS (Breadth-First Search)
- Guarantees the shortest path (if edges are unweighted)
- Works well for grid mazes; time O(V+E)
Pseudocode
```text queue = [start] visited = {start: null} while queue not empty: cur = queue.pop_front() if cur == goal: break for each neighbor in neighbors(cur): if neighbor not in visited: visited[neighbor] = cur queue.push_back(neighbor)path = reconstruct from visited[goal]
```
4) Dijkstra (equivalent to BFS when edges are equal)
- Use for weighted terrains (different movement costs)
- Priority queue recommended; complexity O(E log V)
5) A* (Heuristic Search)
- f(n)=g(n)+h(n); use Manhattan distance for grid mazes
- Reduces expansions and speeds up search under similar heuristics
Speedrun Tips
- Route review: after finishing, revisit key junctions to find potential shortcuts
- Visualization: keep an active mental boundary of unexplored regions
- Rhythm: avoid excessive backtracking; prioritize frontier expansion
Common Pitfalls
- Overusing wall-following in complex mazes
- Failing to mark junctions, leading to repeated exploration
Practice & Tools
- Play online: /maze ยท /maze-runner
- Algorithm demos: /maze-algorithms
FAQ
Is A* always faster than BFS? Not necessarily. BFS can be very fast on certain structures; A* shines by expanding fewer nodes.How to practice on mobile?
Use touch swipe controls; start with low complexity and ramp up gradually.