// Algorithm Referenced from:
//Java Graphic Tutorial, http://www3.ntu.edu.sg/home/ehchua/programming/java/javagame_tictactoe_ai.html
//PLAYING WITH GAME THEORY, https://gangsterveggies.wordpress.com/tag/alpha-beta-pruning/
//improving the prunning algorithm
public static result prunning(int a, int b, char player, int alpha, int beta)
{
result r2 = new result();
int x1 = -1, y1 = -1;
int bestValue = (player == 'X') ? -10 : 10;
if (checkResult() != 0)
{
r2.x = a;
r2.y = b;
r2.val = checkResult();
return r2;
}
if (player == 'X')
{
bestValue = -10;
// List<char[,]> adjList = new List<char[,]>();
// Action( ref adjList, player);
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (boardJim[i, j] == ' ')
{//If legal,
boardJim[i, j] = 'X';
int score = prunning(i, j, 'O', alpha, beta).val;
if (score > alpha)
{
alpha = score;
// bestValue = score;
r2.val = score;
r2.x = i;
r2.y = j;
// move = i;
}//Pick the one that's worst for the opponent
boardJim[i, j] = ' ';//
if (alpha >= beta) break;
}
}
}
return r2;
}
if (player == 'O')
{
bestValue = 10;
// List<char[,]> adjList = new List<char[,]>();
// Action( ref adjList, player);
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (boardJim[i, j] == ' ')
{//If legal,
boardJim[i, j] = 'O';
int score = prunning(i, j, 'X', alpha, beta).val;
if (score < beta)
{
beta = score;
// bestValue = score;
r2.val = score;
r2.x = i;
r2.y = j;
// move = i;
}//Pick the one that's worst for the opponent
boardJim[i, j] = ' ';//
if (alpha >= beta) break;
}
}
}
// return r2;
}
// r2.x = x1;
// r2.y = y1;
// r2.val = bestValue;
return r2;
}
//the computer makes the move through this function by calling minimax
//does accept any parameter, nor gives an output
public static result computerMove()
{
result r1 = new result();
r1 = minimax(0, 0, 'X');
// r1 = prunning(0, 0, 'X', -10, 10);
if (r1.val == 1 || r1.val == 0)
boardJim[r1.x, r1.y] = 'X';
else boardJim[r1.x, r1.y] = 'O';
//board[r1.x, r1.y] = r1.val;
// Form1 f = new Form1();
//f.computerClick(r1.x, r1.y);
return r1;
}