[Delphi] Recursive TicTacToe AI

programming
1

Now this should be easy but for some reason I’m having a lot of trouble with it.

I didn’t want to simply download a source code and implement it, I wanted to try and work it out, but Im not having much luck.


type
  Matrix = array[1..3,1..3] of char;
  Coordinate =
  record
    x,y:integer;
  end;

....

function FindBestMove(nMat:matrix; c:char):Coordinate;
var bestMove:coordinate;
    newCoord:coordinate;
    found:boolean;
    j:Integer;
    k:Integer;
begin
  found := false;
  if GetPossibleMoves(nMat) = 1 then //If only one find the last square (even though its inefficient as of now, but thats just temporary)
  begin
    while not found do
    begin
      newCoord.x:=Random(3)+1;
      newCoord.y:=Random(3)+1;
      found:=nMat[newCoord.x,newCoord.y]=' ';
    end;
    FindBestMove := newCoord;
    Exit;
  end;
  bestMove.x := 0; bestMove.y := 0;

  //Check for a winning square, if theres more than one empty
  for j := 1 to 3 do
  begin
    for k := 1 to 3 do
      begin
        newCoord.x:=j; newCoord.y:=k;
        if (nMat[newCoord.x,newCoord.y]=' ') then
        begin
          nMat[newCoord.x,newCoord.y] := c;
          showMessage('nkl');
          if CheckWin(nMat,c) then
          begin
            FindBestMove := newCoord;
            showMessage('1st');
            Exit;
          end
          else nMat[newCoord.x,newCoord.y] := ' ';
        end;
      end;
  end;

  //If none win, check for a block
  for j := 1 to 3 do
  begin
    for k := 1 to 3 do
      begin
        newCoord.x:=j; newCoord.y:=k;
        if (nMat[newCoord.x,newCoord.y]=' ') then
        begin
          nMat[newCoord.x,newCoord.y] := c;
          if CheckWin(nMat,Rev(c)) then
          begin
            FindBestMove := newCoord;
            showMessage('2nd');
            Exit;
          end
          else nMat[newCoord.x,newCoord.y]:= ' ';
        end;
      end;
  end;

    //If none win and none block, simply choose an empty square at random.
    found := false;
    while not found do
    begin
      newCoord.x:=Random(3)+1;
      newCoord.y:=Random(3)+1;
      found:=nMat[newCoord.x,newCoord.y]=' ';
    end;
    nMat[newCoord.x,newCoord.y] := c;
    bestMove := FindBestMove(nMat, rev(c)); //Continue to find the best move for the opposite player
    FindBestMove:=bestMove;
end;

However it doesn’t work. At all. :smiley:

Any ideas? Guidance would be great.