# What is sudoku?

Sudoku is a logic puzzle game. The objective of sudoku game is to fill the sudoku square grid with numbers so every column, every row and every 3 x 3 subgrid includes numbers from 1 to 9. The puzzle setter partially fills the grid, which usually has only one solution.

Every sudoku solver has to:

- fill every row with numbers from 1 to 9
- fill every column with numbers from 1 to 9
- fill every 3 x 3 subgrid with numbers from 1 to 9