Sudoku appeared in Japan in 1984 [1] and revolves around the distinct placement of the digits 1-9 within rows, columns and 3x3 squares which form a 9x9 grid.
Varients of Sudoku exist to add further challenge via the addition of further constraints. More information can be found here on the Sudoku Wikipage.
The code solves Sudoku puzzles using depth-first search with backtracking. Along side the puzzle a 2D 'whitelist' array is initialised which contains valid numbers for each grid square. The possible values can be visualised as horizontal nodes within the DFS tree, if this tree is traversed to a node of -1 then a different value is chosen for the parent node.
The purpose is of this publication is to demonstrate projects that I have completed during my time at university and not to provide a platform for existing students to take inspiration from.
The main.py file imports the sudoku solver and passes a puzzle in the form of a 2D numpy array.