hard

Sudoku Solver

Fill the empty cells of a partially completed 9 × 9 Sudoku grid so that every row, column and 3 × 3 box contains each digit 1–9 exactly once. The given puzzle has exactly one solution.

Constraints

board is 9 × 9
Cells contain a digit or "."
A unique solution exists

Examples

in: A standard puzzle with 30 clues

out: The completed grid

Code it yourself

Solve in

Your python code

Test execution is not yet available for this exercise.Practice journal →Draft saved in this browser.

Hints:

Which approach applies?

Choose an approach to check your pattern recognition, or reveal the discussion when you need help.