Allow interactive game play using either the command line or a web-based view (for WordLadder only). Web-based view is launched using localhost.

Goal of Sudoku: Fill in all spaces of the board such that each letter only appears once per row, per column, and per square grid.

Goal of WordLadder: Go from the starting word to the target word by finding words that differ by at most one letter from the previous word.

Example: start: cat target: fig

cat -> pat -> pit -> pig -> fig

Hint, Undo, and Solve functions can be called anytime.

Main function is located in controller.py.