CSP Solver

These python modules use generalized arc-consistency to create an all-purpose constraint satisfaction problem solver. This repository also include some sample use-cases of the solver¹.

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N-Queens Solver

This python script uses the CSP module to solve the generalization of the classic 8 Queens puzzle, and can be invoked using the following command.

python3 nqueens.py <input_file>

Input Format

<input_file> is a plaint text file. The first line contains a number that indicates the value of n, the dimension of the problem. For the classic 8 Queens puzzle, this would be 8. The following n lines contain exactly one character each, which must have one of the following values:

1. An integer representing the 0-indexed position of any queens present in the initial configuration of the chess board
2. - to indicate that there are no queens in corresponding row

To solve a 4 Queens variation of this puzzle, where the initial configuration has a queen in the first column of the third row, you would create the following input file:

4
-
-
0
-

Footnotes

1. For now its only the N Queens example; a battleship solitaire solver will be added soon. ↩