Q: How do we use constraint propagation to solve the naked twins problem?
A: For naked twins, the operation should go through all units; for each unit, find the pairs of box with the same values with length 2; then remove the same digit(s) from the box with length 2 or 3.
Thus, the procedure is:
- iterate over all the units
- for each unit, find the boxes with length 2 (it reduces the problem complexity)
- for each pairs, check if they have the same value
- if the same values, loop over all the boxes in the same unit, and remove the same digit(s)
Q: How do we use constraint propagation to solve the diagonal sudoku problem?
A: The idea is actually the same, and we can also use the same strategies. The only difference to make is that adding the diagnoal units to the unit list and peers accordingly. Thereafter, we can use the same functions to solve the problem (if there is a solution).
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.