using the bridged network of oracle virtual machine python (judge) runs on a real machine (windows), server and clients run on a ubuntu 20.04 (Oracle virtual machine) and communicate to each other through TCP/IP.

python (on real machine) communicates to server (on virtual machine) thorugh zmq

if you don't use my configuration (virtual machine) but 2 separate PCs, it also should work but make sure they are connected without any obstacle (i.e can ping IP or send thourgh socket)

also ensure the ports (for both server-clients and judge-server) are not locked by any anti virus

make sure you installed gcc (I use version 9.3) on the unbuntu-based virtual machine and python (3.7) on the real machine

install package of zmq on virtual machine: sudo apt-get install libzmq3-de

install zmq for python (from pip or whatever)

compile server: gcc -pthread -o server server.c -lzmq

compile client: gcc -pthread -o client client.c

how to run:

1. on real machine, run python (tic_tac_toe.py)
2. on virtual machine, cd to the directory of server, run server
3. run 1st client
4. run 2nd client
5. play the game !!

see detail how to run at https://www.youtube.com/watch?v=J5eWpaGk2Sc

Thw judge in python is adopted and modified from https://medium.com/byte-tales/the-classic-tic-tac-toe-game-in-python-3-1427c68b8874