Sudoku Environment#
We provide here a Jax JIT-able implementation of the Sudoku puzzle game.
Observation#
The observation given to the agent consists of:
board: jax array (int32) of shape (9,9): empty cells are represented by -1, and filled cells are represented by 0-8.action_mask: jax array (bool) of shape (9,9,9): indicates which actions are valid.
Action#
The action space is a MultiDiscreteArray of integer values representing coordinates of the square
to explore and the digits to write in the cell, e.g. [3, 6, 8] for writing the digit 9 in
the cell located on the fourth row and seventh column.
Reward#
The reward is 1 at the end of the episode if the board is correctly solved, and 0 in every
other case.
Termination#
An episode terminates when there are no more legal actions available, this could happen if the board is solved or if the agent finds itself in a dead-end.
Registered Versions 📖#
Sudoku-v0, the classic game on a 9x9 grid, 10000 random puzzles with mixed difficulty are included by default.Sudoku-very-easy-v0, the classic game on a 9x9 grid, only 1000 very-easy random puzzles (>46 clues) included by default.
Using custom puzzle instances#
If one wants to include its own database of puzzles, the DatabaseGenerator can be initialized with any collection of puzzles using the argument custom_boards.
Some references for databases of puzzle of various difficulties:
- https://www.kaggle.com/datasets/rohanrao/sudoku
- https://www.kaggle.com/datasets/informoney/4-million-sudoku-puzzles-easytohard
Difficulty level as a function of number of clues#
Adapted from An Algorithm for Generating only Desired Permutations for Solving Sudoku Puzzle.