This is my solution (written in Go) to be used in order to solve sudokus via command line.
A sudoku is a logic-based, combinatorial number-placement puzzle. In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution (Wikipedia).
The reasons someone would like to solve automatically a sudoku instead of taking it as a personal challenge may vary depending on individual preferences and circumstances that are not necessarily cheating. This could be to check a solution, educative or give you a hand when you are stuck on a puzzle.
Everything has been tested under Ubuntu 22.04.4 LTS and go version 1.21.3.
I have not tested it under windows, but I assume the visual input would fail (better use the string or file format) and the colours will not work as expected, I recommend to use the -nc flag.
The code comes with a Makefile that can be executed with:
make
Alternatively, you can compile it yourself with:
go build -o sudoku-solver.exe main.go input.go output.go
It is recommended but not mandatory to have installed gocyclo, goimports, misspell and golint.
By default, the generated executable file is called sudoku-solver.exe. You can call it with arguments.
$ ./sudoku-solver.exe [FLAGS] [INPUT]
- -a All solutions, displays all solutions instead of just the first one.
- -b Brute-force, it uses brute-force when necessary.
- -bt Brute-force time, time in seconds the brute-force algorithm is allowed to run. If this time is reached a "(+)" will appear next to the Solutions amount output (automatically activates brute-force [-b]). (default 60)
- -ms Max solutions, defines the maximum number of solutions the algorithm will calculate. If this number is reached a "(+)" will appear next to the Solutions amount output.(automatically activates brute-force [-b]). (default 10)
- -nc No color, if set disables the colors of the results.
- -s String format output, displays only the result as a string of 81 digits.
Data should be introduced in one of this three ways:
- String: A 81 digit string that represents the sudoku in writing order (top to bottom, left to right) using zeroes for the unknown cells.
- File: A text file that contains the sudoku we want to solve (spaces are allowed).
- Visual: If no arguments for the sudoku are provided, an empty board will be displayed, fill it manually and press enter.
There are some more features pending to be implemented
- Generate solutions changing lines and rows from a base solved sudoku
- Add execution time
- Add an estimated difficulty
- Search for solutions with concurrency/parallelism
- A goroutine that tells how many solutions have been found so far
- The ability to abort an execution