# Sudoku Solver

Figured it would be fun to try making a sudoku solver. I haven't read
any prior art as of yet, though I might at some point to improve
this. I found [this
dataset](https://www.kaggle.com/datasets/rohanrao/sudoku) to use for
testing and benchmarking; it contains 9 million puzzles. I haven't
included the dataset in this repository as it's quite big (around 1.4
GiB), but you can download the archive from the above link and place
the extracted `sudoku.csv` in the root of this repo and it should
work.

## Building

The program is built with `make(1)`:

```shell
make # or 'make sudoku'
```

## Preparation of Puzzles File

I did some pre-processing of the downloaded `sudoku.csv` file to
reduce the workload of the solver, extracting just the puzzles (the
CSV contains the solutions too) and removing the newlines.

```shell
make puzzles
```

## Preparation of Results File

The results file must exist and be of the right size in order for the
program to run successfully.

```shell
make results
```

## Running

The program can be ran through the Makefile, which will ensure the
binary is built and the puzzles and results files have been prepared:

```shell
make run
```

Or it can of course be ran directly:

```shell
./sudoku
```