Description

The objective of Sudoku is to fill every square in the game board (see below) such that the final game state meets the following constraints: 

1. For an n 2 × n 2 board, every cell must contain a number between 1 and n 2 (inclusive). For example, in the 9×9 board below, every cell must contain a value between 1 and 9. 

2. Every row must contain only unique values. In other words, there can only be one of each value in a row. 

3. Every column must contain only unique values. 

4. Every inner n × n board delineated by bold bordering must contain only unique values. 

5. You must work around the starting values in the board (see below).