Sudoku solver in Nix using a simple backtracking algorithm.
Run the following command, replacing ./puzzle1.txt with the path of a puzzle of your choice (with zeroes representing blank squares). No need to check out the repo.
$ nix eval --impure --raw github:siraben/nix-sudoku#lib.demo --apply 'f: f ./puzzle1.txt'Otherwise, cd into a checkout of repo and run the following command
$ nix-instantiate --eval -E '(import ./sudoku.nix {}).demo ./puzzle1.txt' | jq -r
# or using newer Nix command
$ nix eval --raw --impure --expr '(import ./sudoku.nix {}).demo ./puzzle1.txt'
1 4 3 9 8 6 2 5 7
6 7 9 4 2 5 3 8 1
2 8 5 7 3 1 6 9 4
9 6 2 3 5 4 1 7 8
3 5 7 6 1 8 9 4 2
4 1 8 2 7 9 5 6 3
8 2 1 5 6 7 4 3 9
7 9 6 1 4 3 8 2 5
5 3 4 8 9 2 7 1 6
$ nix eval --raw --impure --expr '(import ./sudoku.nix {}).demo ./puzzle2.txt'
No solution!Beats solving by hand. If you know how to make it faster, please submit PRs!
$ nix run nixpkgs#hyperfine -- "nix-instantiate --eval -E '(import ./sudoku.nix {}).demo ./puzzle1.txt'"
Benchmark 1: nix-instantiate --eval -E '(import ./sudoku.nix {}).demo ./puzzle1.txt'
Time (mean ± σ): 809.3 ms ± 19.5 ms [User: 690.2 ms, System: 100.8 ms]
Range (min … max): 782.9 ms … 846.5 ms 10 runs
Because I could.