Code crossword puzzle solver

How would you make a code crossword puzzle solver?

A code crossword puzzle is a crossword puzzle that, in stead of using key word clues, has numbered all cells in the crossword. Each number corresponds to one letter.

Perhaps make a project where a user can
* define the dimensions of the crossword puzzle
* fill in the numbers for each cell in the crossword
* assign a letter to each value and then fill in the puzzle using those letters

Extra credits for
* Detecting if a letter has been assigned to more than one value
* spell checking the resulting words to find (potential) errors

Double credits for
* Attempting words from a dictionary and finding the best possible solution

Teaching points
* Multi dimensional arrays or tables
* Creating a grid of inputs and using attributes to destinguish them
* Using input change events

I have started such a project myself, and it is kinda working, but I would love to see how you would solve this challenge and how different it would be from my solution.

Thank you for a wonderful series and your continued effort to teach programming!

Best regards

Terje Nilima Monsen