public int MakeTurn(Connect4Board b)
{
int depth = 5;
if (round >= 25) depth = 7;
else if (round >= 32) depth = 100;
double max = -10000.0;
int bestMoveSoFar = 0;
for (int i = 0; i < b.GetNrColumns(); i++)
{
if (b.IsValidMove(i))
{
Connect4Board testBoard = new Connect4Board(b);
testBoard.AddDisc(i, botId);
double moveScore = AlphaBeta(testBoard, depth, -100000.0, 100000.0, false);
//DisplayScore(moveScore, i);
if (moveScore > max)
{
max = moveScore;
bestMoveSoFar = i;
}
}
}
//b.DisplayBoard();
return bestMoveSoFar;
}
public int MakeTurn(Connect4Board b)
{
double max = -10000.0;
int bestMoveSoFar = 0;
for (int i = 0; i < b.GetNrColumns(); i++)
{
if (b.IsValidMove(i))
{
Connect4Board testBoard = new Connect4Board(b);
testBoard.AddDisc(i, botId);
double moveScore = AlphaBeta(testBoard, depth, -10000.0, 10000.0, false);
if (moveScore > max)
{
max = moveScore;
bestMoveSoFar = i;
}
}
}
return bestMoveSoFar;
}
public double AlphaBeta(Connect4Board oldBoard, int d, double alpha, double beta, bool player)
{
if (d == 0 || (CheckForWin(oldBoard) != 0 || CheckForDraw(oldBoard)))
{
return Score(oldBoard);
}
if (player)
{
double val = -100000.0;
for (int i = 0; i < oldBoard.GetNrColumns(); i++)
{
if (oldBoard.IsValidMove(i))
{
Connect4Board newBoard = new Connect4Board(oldBoard);
newBoard.AddDisc(i, botId);
val = Math.Max(val, gamma * AlphaBeta(newBoard, d-1, alpha, beta, !player));
alpha = Math.Max(alpha, val);
if (beta <= alpha) break;
}
}
return alpha;
}
else
{
double val = 100000.0;
for (int i = 0; i < oldBoard.GetNrColumns(); i++)
{
if (oldBoard.IsValidMove(i))
{
Connect4Board newBoard = new Connect4Board(oldBoard);
newBoard.AddDisc(i, (3- botId));
val = Math.Min(val, gamma * AlphaBeta(newBoard, d-1, alpha, beta, !player));
beta = Math.Min(val, beta);
if (beta <= alpha) break;
}
}
return beta;
}
}
