private MCTSTreeNode(MCTSTreeNode parrent)
{
this.parrent = parrent;
this.scoreSum = 0;
this.nVisited = 1;
succesors = new List <MCTSTreeNode>();
}
public MCTSTreeNode selectSuccesor()
{
if (this.isLeaf)
{
return(this);
}
double max = -10;
MCTSTreeNode bestSuccesor = null;
foreach (var item in succesors)
{
if (item.isFinished)
{
continue;
}
double val = item.eval();
if (val > max)
{
max = val;
bestSuccesor = item;
}
}
if (bestSuccesor == null)
{
this.isFinished = true;
bestSuccesor = succesors[0];
}
return(bestSuccesor.selectSuccesor());
}
public void expand()
{
if (isFinished)
{
return;
}
if (position.hasFinished)
{
isFinished = true;
return;
}
this.isLeaf = false;
List <Action> possibleActions = position.generatePossibleActions();
if (possibleActions.Count == 0)
{
throw new Exception();
}
foreach (var item in possibleActions)
{
MCTSTreeNode succesor = createLeaf(this, item);
succesor.position = this.position.clone();
succesor.position.playMove(item.player, item.number);
succesors.Add(succesor);
if (succesor.position == null)
{
throw new Exception();
}
}
this.position = null;
this.updateSubtreeSize(possibleActions.Count);
this.updateSubtreeDepth(1);
}
public static MCTSTreeNode createLeaf(MCTSTreeNode parrent, Action move)
{
MCTSTreeNode node = new MCTSTreeNode(parrent);
node.isLeaf = true;
node.action = move;
return(node);
}
public static MCTSTreeNode createRoot(Game position)
{
MCTSTreeNode node = new MCTSTreeNode();
node.succesors = new List <MCTSTreeNode>();
node.parrent = null;
node.scoreSum = 0;
node.nVisited = 1;
node.isLeaf = true;
node.position = position;
return(node);
}