Problem

• Currently uses the brute force approach
• Some puzzles take 10+minutes (though this is mainly due to the animation)

Solution

• Implement more efficient solvers
  • See https://en.wikipedia.org/wiki/Sudoku_solving_algorithms
  • In particular: https://en.wikipedia.org/wiki/Dancing_Links
• Create a dropdown component to swap solver algorithms

Currently using class components.

Currently the only way to cancel the solve is by refreshing the page. Should add a cancel button.

Currently log to console reasons why input is invalid. Should put something in the UI.

Achieve 90%+ codecov.

Not sure what best practices are for testing React apps. Will have to research this.

Will need input validation e.g. they can only enter 1-9 for a cell, and inputs shouldn't invalidate the board (e.g. can't enter a 9 when that row already has a 9).

Currently logs to console "Unsolveable board" should put something in the UI.