Files
scrabble-solver/scrabble/gen.go
T
Ilia Denisov 15c7959d96 Implement Scrabble move generator (DAWG) with English and Russian rules
A Go library that returns every legal play ranked by score and scores or
validates plays, using the Appel-Jacobson DAWG algorithm over
github.com/iliadenisov/dafsa v1.1.0.

- DAWG move generation (across / down / both), full tournament scoring with a
  per-tile breakdown; public Solver: GenerateMoves (ranked), ScorePlay,
  ValidatePlay.
- Rulesets: English Scrabble, Russian Scrabble, Эрудит (parameterizable Ruleset).
- cmd/builddict (build the DAWG from the dictionaries submodule), cmd/stress
  (self-play benchmark), selfplay engine; brute-force test oracle.
- A GADDAG was implemented, benchmarked and removed (the DAWG was smaller and
  faster for a scoring solver); see RESULTS.md and ALGORITHM.md.
2026-06-01 16:07:32 +02:00

57 lines
1.7 KiB
Go

package scrabble
import (
"scrabble-solver/board"
"scrabble-solver/rack"
"scrabble-solver/rules"
)
// generateBoth runs an across-generator on the board (for horizontal plays) and on its
// transpose (for vertical plays), as selected by mode, then scores and de-duplicates the
// results. runAcross reports placements in the coordinates of the board it is given; for
// the transpose pass they are mapped back to the real board.
func generateBoth(b *board.Board, rs *rules.Ruleset, rk rack.Rack, mode Mode,
runAcross func(bd *board.Board, rk rack.Rack, emit func([]Placement))) []Move {
rk = rk.Clone() // generation mutates the rack in place and restores it
var moves []Move
seen := make(map[string]struct{})
emit := func(dir Direction, placements []Placement) {
key := moveKey(dir, placements)
if _, dup := seen[key]; dup {
return
}
m, err := Evaluate(b, rs, dir, placements)
if err != nil {
return
}
seen[key] = struct{}{}
moves = append(moves, m)
}
if mode.Includes(Horizontal) {
runAcross(b, rk, func(p []Placement) { emit(Horizontal, p) })
}
if mode.Includes(Vertical) {
tb := b.Transpose()
runAcross(tb, rk, func(p []Placement) {
rp := make([]Placement, len(p))
for i, pl := range p {
rp[i] = Placement{Row: pl.Col, Col: pl.Row, Letter: pl.Letter, Blank: pl.Blank}
}
emit(Vertical, rp)
})
}
return moves
}
// centerFor returns the centre square in bd's coordinates. bd is either the real board
// or its transpose; the ruleset stores the centre on the real board.
func centerFor(bd *board.Board, rs *rules.Ruleset) (row, col int) {
r, c := rs.Center/rs.Cols, rs.Center%rs.Cols
if bd.Rows() == rs.Rows && bd.Cols() == rs.Cols {
return r, c
}
return c, r // transposed
}