Connect Four written in C to practice C
- Write Connect Four Two Player
- Write AI (https://en.wikipedia.org/wiki/Minimax)
- Write alpha-beta pruning optimisation
- Bitboard optimisation (https://en.wikipedia.org/wiki/Bitboard)
- GUI Game (https://www.raylib.com/ or SDL)
- Further heuristic optimisations
- Refactor
cd to the directory and run make to compile. The executable binaries will be in the same directory.
./gui/ (Graphical Connect Four written using the SDL development library) ./cli/ (Command-line Connect Four written in pure C)
A little bit about the implementations. The latest implementations are using bitboards to store the board position. Here is a benchmark of the different implementations (you can find the older implementations in archive/). Done on a Ryzen 5 3600 with AI picking first
| Implementation | Depth | Time (s) | Visited nodes |
|---|---|---|---|
| 2D Array Board AI | 7 | 1.250252 | 6634026 |
| 2D Array Board AI | 8 | 4.637645 | 46028598 |
| 2D Array Board AI | 9 | 32.516463 | 314060244 |
| "Pseudo-bitboard" AI | 7 | 0.171348 | 6602778 |
| "Pseudo-bitboard" AI | 8 | 1.180703 | 45414144 |
| "Pseudo-bitboard" AI | 9 | 8.299119 | 310985082 |
| Bitboard AI (latest) | 7 | 0.051276 | 6601433 |
| Bitboard AI (latest) | 8 | 0.384628 | 45386033 |
| Bitboard AI (latest) | 9 | 2.373259 | 310528499 |
Explanation about the development process here.