Unfortunately the remainder of this challenge is not so exciting. After part 2, I've actually successfully completed the conditions (simulating game board, placement of pieces, and an optimized victory checking algorithm!)
So we've discussed the design decision behind the board, the pieces, and the representation of the board. Let's continue with talking about the algorithmic optimizations for checking the victory condition.
I recently had a programming challenge for an interview that required me to code a "functional" version of Connect. I explain some of my design decisions here
