Solver

bananagrams hands you a fistful of letter tiles and one instruction: arrange all of them into a connected crossword before anyone else does. 𐃏 this page documents the real solver living in this repo at static/code/bananagrams/ — a haskell heuristic search in haskell-imp/ plus a playable js incarnation served at /code/bananagrams/ on this site — rather than a from-scratch design; a compact python reference solver (trie + backtracking) is developed at the end to make the algorithmic skeleton explicit.

hashiwokakero (“build bridges”, nikoli) hands you a grid of numbered islands and asks you to join them with bridges until every number is spent. it is the friendliest possible introduction to constraint satisfaction: the constraints are few and visual, propagation alone solves most human-published puzzles, and when it doesn’t, you get to write a backtracking search. this page documents my solver at code/private/hashi/ — a go rewrite of a uni assignment originally in c — including the debugging session that writing this page forced on it. 𐃏