Connect-4 is a Two player board game published on 1974. The game has sustained its legendary status in the board game community, and forever will be one of the more remembered and iconic board games. The game is simple enough that anyone who wants to play could learn it in a few minutes and play it off of intuition, but to perfect the art of playing, might take years for some...
As mentioned before, Connect-4 is a Two player game, meaning that in order to play it you must find an opponent to play against. Board games are fun to play in-person, but we don't always have someone to play with.
The project has Two main sections to play.
The First, is playing online. The project has a multiplayer section which allows users to connect through the internet to a server and play each other from anywhere in the world. The players can access a leaderboard and chat with each other.
And the Second, is choosing the level of a computer and playing an AI. The player will first choose the wanted difficulty, then play a program with that difficulty.
Both options allow nice functionality and solve the problem in Two different ways which together present a great result.
The two main technologies I have used to create this project are in both sections (multiplayer and single-player).
For the multiplayer section, the technology I used for communication is multithreading Networking with a connection based protocol - the TCP protocol. Both players establish a connection with the server, send their moves and get a response. once the server receives a move from either player, it sends back a response and notifies the other player. Simplified, the protocol is based on stable connection between two computers and a stream of data instead of individual packets (UDP).
For the single player section, I have chose an algorithmic approach for the problem of designing an engine. The most important algorithm in my implementation is the "Alpha-Beta pruning" algorithm. The algorithm helps with making decisions on which moves to make, and evaluating a given game position based on the future positions ahead. Simplified, every move a player has 7 (or less) moves to choose from, and for each move there are 7 (or less) more responses of the opponent. The algorithm recursively prunes branches based on their evaluation, and doesn't play moves that favor the opponent. The difficulty of the "AI" player can be controlled by altering the depth of the recursive search.