Q: How do we use constraint propagation to solve the naked twins problem?
A: The naked twins heuristic allow to reduce the alternatives in a group
with naked twins. Naked twins strategy allow the elimination of these pair
of numbers in the units in which they appear. The is being repeatedly
perform taking advantage of bread first search to solve a given Sudoku.
Q: How do we use constraint propagation to solve the diagonal sudoku problem?
A: Constraint propagation is about using local constraints in a space to
dramatically reduce the search space. In terms, of the diagonal sudoku this
can be achieved by defining the proper peers to the boxes that belongs to a
specific diagonal to guarantee that the values appear only one in each diagonal.
Then constraint propagation will make use of different heuristics such as
elimination, only choice and naked twins to solve a certain Sudoku.
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 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.