Q: How do we use constraint propagation to solve the naked twins problem?
A: Once we have found a set of naked twins, we can use constraint propagation by applying an iterative attempt to remove values from the surrounding peers. The removal of these digits will be based on the constraint that they appears within our naked twins, and thus may not appear in any peer boxes.
We will iteratively apply, or propagate this constrain to all peers of the naked twins until it can no longer be applied.
Q: How do we use constraint propagation to solve the diagonal sudoku problem? A: In order to solve the diagonal sudoku an additional unit needs to be applied - the two diagonal units. Once an additional unit is added to our traditional units of rows, columns and squares, the same strategies of constraint propagation that is iteratively applied until either success or a non-new puzzle state can be applied.
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_values
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](https://project-assistant.udacity.com/auth_tokens/jwt_login 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.