Can you explain the backtracking algorithm for solving Sudoku?

Can you explain the backtracking algorithm for solving Sudoku?

Sure! The backtracking algorithm is a recursive method used to solve constraint satisfaction problems like Sudoku. It tries to fill the grid by placing numbers in empty cells and checks if the current configuration is valid.

How does the algorithm know if a configuration is valid?

The algorithm checks if the number placed in a cell does not violate Sudoku rules: each number must be unique in its row, column, and 3x3 subgrid.

What happens if a number leads to an invalid configuration?

If a number leads to an invalid configuration, the algorithm backtracks by removing the number and trying the next possible number in that cell.

Can you give me a simple example of how it works?

Absolutely! Let's say we start with an empty cell. The algorithm will try placing '1', check validity, then '2', and so on, until it finds a valid number or backtracks if needed.