// Min part of Minimax with AB pruning
private int MiniABPruning(PositionManager board, int depth, int a, int b)
{
if (depth <= 0)
{
return(board.GetValueOfBoard());
}
int min = int.MaxValue;
List <(int, int)> allPM = MoveManager.GetAllPossibleMoves(board, false, false);
if (allPM.Count == 0)
{
return(board.GetValueOfBoard());
}
foreach ((int, int)iMove in allPM)
{
PositionManager childBoard = new PositionManager(board);
childBoard.MovePiece(iMove.Item1, iMove.Item2);
min = Math.Min(min, MaxABPruning(childBoard, depth - 1, a, b));
b = Math.Min(b, min);
if (b <= a)
{
break;
}
}
return(min);
}
// Minimax main function, should be the one to call in all cases
// Essentialy the same as MinABPruning but store the actual move
private (int, int) MiniMaxABPruning(int n)
{
(int, int)move = (-1, -1);
int min = int.MaxValue;
List <(int, int)> allPM = MoveManager.GetAllPossibleMoves(realBoard, false, false);
foreach ((int, int)iMove in allPM)
{
PositionManager childBoard = new PositionManager(realBoard);
childBoard.MovePiece(iMove.Item1, iMove.Item2);
int score = MaxABPruning(childBoard, n, int.MinValue, int.MaxValue);
if (score == min && (Random.Range(0, 2) == 0)) //add random to make the AI less predictable
{
move = iMove;
}
if (score < min)
{
min = score;
move = iMove;
}
}
if (min > 300)
{
return(-1, -1);
}
return(move);
}
private (int, int) PlayRandom()
{
List <(int, int)> allPM = MoveManager.GetAllPossibleMoves(realBoard, false, false);
(int, int)move = allPM[Random.Range(0, allPM.Count)];
realBoard.MovePiece(move.Item1, move.Item2);
return(move);
}
