Sudoku Checker

The purpose of this exercise is to code a simple sudoku checker.

That is, a program that tells us if a sudoku solution is right or wrong.

From Wikipedia:

Sudoku (数独, sūdoku, digit-single) (/suːˈdoʊkuː, -ˈdɒk-, sə-/, originally called Number Place)[1] is a logic-based,[2][3] combinatorial[4] 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") contain 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.

To take a quick overview, this is an unsolved Sudoku:

and it's solution:

Rules

To solve a sudoku there are only three rules:

1. Not repeated numbers in each row
2. Not repeated numbers in each column
3. Not repeated numbers in each 3x3 cell.

Files in this repository

In this repo you have some interesting resources:

• data/right.csv contains a CSV file with a right solved sudoku.
• data/wrong.csv contains a CSV file with a wrong solved sudoku.
• app.php it's an entrypoint to execute a sudoku validation. Feel free to change it as you need.
• src/SudokuChecker.php it's a class intended to be the sudoku checker. Feel free to change it as you need.

Feel free to install new third-party dependencies if you need it, except (obviously) for that ones which perform sudoku validations ;)

Happy coding!