Category : Files from Magazines
Archive   : ITP9004.ZIP
Filename : QUEENS.PAS

{************************************************
* QUEENS - solve the classical 'Queens' problem *
* FOR a board OF size n. The problem is TO put *
* n Queens (chess pieces) on an n x n board so *
* that no queen can attack any OF The others. *
* This IMPLEMENTATION will print The number OF *
* solutions found FOR each board size, from 1 *
* TO 9 squares on a side. *
* *
* 900125 MCMason - originally coded *
*************************************************}

{The Queen1 unit initially solves the puzzle,
substitute queen2 and queen3 in the $Define
compiler directive for alternative algorithms}


{$DEFINE QUEEN1}

{$IFDEF QUEEN1}
USES QUEEN1;
{$ENDIF}

{$IFDEF QUEEN2}
USES QUEEN2;
{$ENDIF}

{$IFDEF QUEEN3}
USES QUEEN3;
{$ENDIF}


VAR
TotalSolns : Integer; {Total solns/all sizes}
I : Integer;


BEGIN
TotalSolns := 0;

{ Print table heading }

WriteLn('# Queens # solns Total #');
WriteLn('# Brd sz this sz solns');
WriteLn('-------- ------- -------');

{Find the number of solutions for each}
{board size, and print the table entry.}

FOR I :=1 TO 9 DO
BEGIN
InitBoard; {Clear the board}
{Solve the problem}
Queens(0,I); {Start @ column 0}
{Print summary}
Inc(TotalSolns,solns);
WriteLn(I:6,solns:13,TotalSolns:10)
END;

{Print end of table footer}

WriteLn('-------- ------- -------')
END.