Q: How do we use constraint propagation to solve the naked twins problem?
A: In the naked twins problem, we have two boxes within a unit that have only two potential values which are the same. By process of elimination, we know that
each of these two boxes must contain one of these two values, so no other peers could possibly have those two values. Because of this, we can loop through all the
peers within that unit and eliminate these two values as possibilities.
Q: How do we use constraint propagation to solve the diagonal sudoku problem?
A: In the diagonal sudoku problem, we are adding the concept of a new set of peer units along the main diagonals of the sudoku matrix. As we did with the other peer
units within the sudoku, we iteratively narrow the possibilities for each square within these diagonals, always ensuring that any given number 1-9 appears exactly
once in the main 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.
solution.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_value function provided in solution.py
Before submitting your solution to a reviewer, you are required to submit your project to Udacity's Project Assistant, which will provide some initial feedback.
The setup is simple. If you have not installed the client tool already, then you may do so with the command pip install udacity-pa.
To submit your code to the project assistant, run udacity submit from within the top-level directory of this project. You will be prompted for a username and password. If you login using google or facebook, visit this link for alternate login instructions.
This process will create a zipfile in your top-level directory named sudoku-.zip. This is the file that you should submit to the Udacity reviews system.