Simple command line interface implementation of the classic game of Connect Four.
Two players take turns, and indicate their desired move by specifying the 0-indexed column in which they wish to place their piece. (The options for valid move columns are 0-6, inclusive.)
Here's what an empty board looks like:
[0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0]
[0, 0, 0, 0, 0, 0, 0]
A winning combination of four-in-a-row can be achieved horizontally, vertically, or diagonally.