Q: How do we use constraint propagation to solve the naked twins problem?
A: We look for two squares in the same unit that both have the same two possible digits. In Sudoku this imposes a constraint on the peers of these squares. So we remove these values from the peers of both squares.
Q: How do we use constraint propagation to solve the diagonal sudoku problem?
A: We use our three constraints on our units: elimination, only choice and naked twins. By adding diagonal units to our original unit list, we satisfy constraint propagation to these diagonals.
This project requires Python 3.
We recommend students install Anaconda, a pre-packaged Python distribution that contains all of the necessary libraries and software for this project. Please try using the environment we provided in the Anaconda lesson of the Nanodegree.
Optionally, you can also install pygame if you want to see your visualization. If you've followed our instructions for setting up our conda environment, you should be all set.
If not, please see how to download pygame here.
solutions.py
- You'll fill this in as part of your solution.solution_test.py
- Do not modify this. You can test your solution by runningpython solution_test.py
.PySudoku.py
- Do not modify this. This is code for visualizing your solution.visualize.py
- Do not modify this. This is code for visualizing your solution.
To visualize your solution, please only assign values to the values_dict using the assign_values
function provided in solution.py
The data consists of a text file of diagonal sudokus for you to solve.