I recently had the chance to employ this one, but didn’t manage to: it turns out that four three-to-six-year-olds are not especially interested in putting down markers and following rules, they just want to run around the maize maze and say “maize maze” and make “amazing” jokes1
Tremaux’s algorithm is a method for finding your way out of a maze by putting down markers to show where you’ve been. Assuming the maze has well-defined passages and junctions, here’s what you do:
This algorithm guarantees finding an exit if it exists; a path (not necessarily the shortest path) from the starting point to the exit can be found by following all of the passage entrances and exits with a single marker.
It gets you out of mazes. Next!
Oh, all right. It’s a particular case of a depth-first search which has applications in graph theory - particularly in finding spanning trees of graphs, infinite or otherwise.
Charles Pierre Tremaux (1859-1882) is another hard-to-track down character from the history of maths. He’s referred to as ‘an author’, possibly from Charrecey in Burgundy. Edouard Lucas refers to him as an ex-student of the Ecole Polytechnique and a telegraph engineer.
As always, if you know more or better, I’d love to hear about it!