Algorithm Performance For Chessboard Separation Problems

R.Douglas Chatham1, Maureen Doyle2, John J. Miller2, Amber M. Rogers2, R. Duane Skaggs1, Jeffrey A. Ward 2
1Department of Mathematics and Computer Science, Morehead State University, Morehead, Kentucky 40351 USA
2Department of Computer Science, Northern Kentucky University, Highland Heights, Kentucky 41099 USA

Abstract

Chessboard separation problems are modifications to classic chessboard problems, such as the \( N \) Queens Problem, in which obstacles are placed on the chessboard. This paper focuses on a variation known as the \( N + k \) Queens Problem, in which \( k \) Pawns and \( N + k \) mutually non-attacking Queens are to be placed on an \( N \)-by-\( N \) chessboard. Results are presented from performance studies examining the efficiency of sequential and parallel programs that count the number of solutions to the \( N + k \) Queens Problem using traditional backtracking and dancing links. The use of Stochastic Local Search for determining the existence of solutions is also presented. In addition, preliminary results are given for a similar problem, the \( N + k \) Amazons.