Eight Queens Puzzle - Sample Program

Sample Program

The following is a Pascal program by Niklaus Wirth. It finds one solution to the eight queens problem.

program eightqueen1(output); var i : integer; q : boolean; a : array of boolean; b : array of boolean; c : array of boolean; x : array of integer; procedure try( i : integer; var q : boolean); var j : integer; begin j := 0; repeat j := j + 1; q := false; if a and b and c then begin x := j; a := false; b := false; c := false; if i < 8 then begin try( i + 1, q); if not q then begin a := true; b := true; c := true; end end else q := true end until q or (j = 8); end; begin for i := 1 to 8 do a := true; for i := 2 to 16 do b := true; for i := -7 to 7 do c := true; try( 1, q); if q then for i := 1 to 8 do write( x:4); writeln end.

Read more about this topic:  Eight Queens Puzzle

Famous quotes containing the words sample and/or program:

    All that a city will ever allow you is an angle on it—an oblique, indirect sample of what it contains, or what passes through it; a point of view.
    Peter Conrad (b. 1948)

    Cole’s Hill was the scene of the secret night burials of those who died during the first year of the settlement. Corn was planted over their graves so that the Indians should not know how many of their number had perished.
    —For the State of Massachusetts, U.S. public relief program (1935-1943)