Chapter 13, Problem 24PE

Program Plan Intro

  To refine the eight queens problem

Program plan:

• In the file “Queen.java”, create a class “Queen”,
  • Declare necessary variables.
  • Define the constructor to construct a queen at a given position.
  • Define a method “attacks()” to check whether the queen attacks another.
  • Define a method “toString()” to get the formatted string.
  • Define a method “equals()” to check whether both objects are equal.
• In the file “PartialSolution.java”, create a class “PartialSolution”,
  • Declare an array of “Queen” objects.
  • Initialize necessary variables.
  • Define the constructor to construct a partial solution of a given size.
  • Define a method “examine()” to examine a partial solution.
  • Define a method “extend()” to produce all extensions of the partial solution.
  • Define a method “toString()” to get the formatted string.
• In the file “EightQueens.java”, create a class “EightQueens”,
  • Define the “main()” method,
    • Create “PrintWriter” object.
    • Print the content.
    • Call the method “solve()”.
    • Define a method “solve()” to print all solutions to the problem that can be extended from a given partial solution.