Sudoku solver using recursion. Can be solved by user in the pygame GUI, where the program allows you to lock in your guess if it is correct, otherwise you get a 'strike'. Your guess is input temporarily, and if you confirm the guess with 'enter' then the program checks if it is a solution. By pressing 'space' the program auto-solves the sudoku and gives you the full solution. This is visualized, and a snippet of one auto-solution is shown in the GIF below:
Requirements: python3 and pygame