public bool OpponentCanWin(Node currentPosition)
{
bool canWin = false;
List <Piece> possiblePieceForcedToMove = currentPosition.gameState.ScanForAllForcedPiece();
if (possiblePieceForcedToMove.Count > 0)
{
foreach (Piece selectedPiece in possiblePieceForcedToMove)
{
CheckerBoard lookAhead = gameObject.AddComponent <CheckerBoard>();
lookAhead = currentPosition.gameState;
List <Vector2> possiblePositionsToMoveTo = selectedPiece.possiblePositionForcedToMoveTo;
startDrag = gameState.UpdateDrag(selectedPiece);
foreach (Vector2 possiblePosition in possiblePositionsToMoveTo)
{
endDrag = possiblePosition;
currentPosition.ChangeMovingInState((int)startDrag.x, (int)startDrag.y, (int)endDrag.x, (int)endDrag.y);
if (lookAhead.CheckVictory(state) == 1)
{
canWin = true;
break;
}
}
}
}
else
{
List <Piece> possiblePieceToMove = gameState.ScanForAllPiecePossibleToMove();
if (possiblePieceToMove.Count > 0)
{
foreach (Piece selectedPiece in possiblePieceToMove)
{
CheckerBoard lookAhead = gameObject.AddComponent <CheckerBoard>();
lookAhead = currentPosition.gameState;
List <Vector2> possiblePositionsToMoveTo = selectedPiece.possiblePositionForcedToMoveTo;
startDrag = gameState.UpdateDrag(selectedPiece);
foreach (Vector2 possiblePosition in possiblePositionsToMoveTo)
{
endDrag = possiblePosition;
currentPosition.ChangeMovingInState((int)startDrag.x, (int)startDrag.y, (int)endDrag.x, (int)endDrag.y);
if (lookAhead.CheckVictory(state) == 1)
{
canWin = true;
break;
}
}
}
}
}
return(canWin);
}
public void selectAction()
{
LinkedList <Node> visited = new LinkedList <Node>();
Node cur = this;
visited.AddLast(this);
// if not win and cur is a leaf
if (gameState.CheckVictory(state) == -9)
{
cur.expand();
Node newNode = cur.select();
gameState.Moving((int)newNode.state[65], (int)newNode.state[66], (int)newNode.state[67], (int)newNode.state[68]);
if (newNode != null)
{
//newNode.GetCurrentCheckerBoard();
visited.AddLast(newNode);
// caculate value of all child node
double value = rollOut(newNode);
foreach (Node node in visited)
{
node.updateStats(value);
}
}
else
{
Debug.LogError("select action selected a null node");
}
}
else
{
double value = 0;
switch (cur.gameState.CheckVictory(state))
{
case 8:
value = 1.0;
break;
case -8:
value = 0.0;
break;
default:
break;
}
foreach (Node node in visited)
{
node.updateStats(value);
}
}
//return
}
public double rollOut(Node tn)
{
CheckerBoard rollGS = gameObject.AddComponent <CheckerBoard>();
rollGS = tn.gameState;
bool stillPlaying = true;
double rc = 0;
int pos;
int move;
List <Piece> possiblePieceForcedToMove = rollGS.ScanForAllForcedPiece();
if (possiblePieceForcedToMove.Count > 0)
{
while ((possiblePieceForcedToMove.Count > 0) && stillPlaying)
{
pos = r.Next(possiblePieceForcedToMove.Count - 1);
startDrag = gameState.UpdateDrag(possiblePieceForcedToMove[pos]);
List <Vector2> possiblePositionsToMoveTo = possiblePieceForcedToMove[pos].possiblePositionForcedToMoveTo;
move = r.Next(possiblePositionsToMoveTo.Count - 1);
endDrag = possiblePositionsToMoveTo[move];
tn.ChangeMovingInState((int)startDrag.x, (int)startDrag.y, (int)endDrag.x, (int)endDrag.y);
switch (rollGS.CheckVictory(state))
{
case -9: // 1 won - ai
stillPlaying = false;
if (!rollGS.whoseMove())
{
rc = 1.0;
}
break;
default: /* keep playing */
possiblePieceForcedToMove = rollGS.ScanForAllForcedPiece();
break;
}
}
}
else
{
List <Piece> possiblePieceToMove = gameState.ScanForAllPiecePossibleToMove();
while ((possiblePieceToMove.Count > 0) && stillPlaying)
{
pos = r.Next(possiblePieceToMove.Count - 1);
startDrag = gameState.UpdateDrag(possiblePieceToMove[pos]);
List <Vector2> possiblePositionsToMoveTo = possiblePieceToMove[pos].possiblePositionToMoveTo;
move = r.Next(possiblePositionsToMoveTo.Count - 1);
endDrag = possiblePositionsToMoveTo[move];
tn.ChangeMovingInState((int)startDrag.x, (int)startDrag.y, (int)endDrag.x, (int)endDrag.y);
switch (rollGS.CheckVictory(state))
{
case -9: // 1 won - ai
stillPlaying = false;
if (!rollGS.whoseMove())
{
rc = 1.0;
}
break;
default: /* keep playing */
possiblePieceToMove = rollGS.ScanForAllForcedPiece();
break;
}
}
}
return(rc);
}
