Maze Solver

A hedge maze is generated fresh every run, with one path from the mouse's hole in the top-left corner to the cheese in the bottom-right. The Genetic Algorithm evolves a plan: a signpost in every cell that tells the mouse which way to go. There is no per-step thinking. The whole route is decided in advance, and the GA improves that route generation by generation.

How it works

1. Each candidate is one signpost per cell. Each time the mouse stands on a cell, its signpost picks one of the open ways on, or turns back the way the mouse came. Random plans dither and double back; good plans learn which branch to take at each fork.
2. Fitness rewards getting closer to the exit, with a large jump for reaching it and a bonus for reaching it in fewer steps.
3. The fittest plans become parents. Their moves are recombined and mutated to seed the next generation.
4. Press Reset for a brand new maze and a fresh population.

What to watch

• Early generations wander into dead ends and double back.
• The best plan steadily reaches deeper into the maze, and with Show all paths on you see every other plan of the generation spread out behind it.
• Eventually a plan threads the whole maze to the cheese and its route glows. Later plans do it in fewer moves until the route is the shortest one: compare Plan with Shortest in the stats bar.