A minimal web-based application to play N-queens, where the objective is to place N queens on an N x N chessboard where none of the queens may attack each other.
In each step, the player selects a field on the chessboard to place a queen. After each step, a CP solver checks if there exists a solution for the current placement of queens.
The application uses Python Flask as web-server and MiniZinc with built-in CP solver Gecode for checking feasibility of the player's moves.
This code was inspired by the MiniZinc web servers from https://github.com/Imvoo/MiniZinc-server.
The application requires Python 3.5 (or higher) and it is recommended to setup a virtual
environment for Python. Install all required Python libraries listed in requirements.txt
using the command the pip install -r requirements.txt in your terminal.
You will also need to install MiniZinc 2.2.1 (or a newer version).
After downloading the binary bundle, make sure that minizinc is in your path. You can
test this by typing minizinc into your terminal and check if the program can be executed.
To achive this under Linux, you will first need to add MiniZinc's bin/directory
to your the $PATH environment variable, and add MiniZinc's lib/ directory to
LD_LIBRARY_PATH:
export PATH=$PATH:/path/to/minizinc/bin
export LD_LIBRARY_PATH=/path/to/minizinc/lib/:$LD_LIBRARY_PATH
To run the game on your localhost, open a terminal, enter your Python virtual enviroment if
have set it up, and set the $FLASK_APP environment variable:
export FLASK_APP=server.py
Then run flask with the command:
flask run
Finally, use your favourite browser to navigate to http://localhost:5000/nqueens-game to start playing the game.
LICENSE the software license
requirements.txt the file containing the required Python libraries
server.py Flask server file
templates/start.html The template dynamic HTML file when starting the game
templates/queens_state.html The template dynamic HTML file for playing the game
minizinc/queens.mzn MiniZinc problem model for the N-queens problem