public double BuildABTree(StishMiniMaxNode CurrentNode, int DepthCount, double Alpha, double Beta, int colour)
{
if (CurrentNode == null || DepthCount == 0)
{
//returns if this is the root node or is a leaf node
return(colour * CurrentNode.FindValue(CurrentNode, CurrentNode.NodeBoardState, CurrentNode.Allegiance));
}
double Value = double.MinValue;
double ChildValue;
ForeSight.Instance.GenerateChildren(CurrentNode);
for (int index = 0; index < CurrentNode.CountChildren(); index++)
{
ChildValue = -1 * BuildABTree((StishMiniMaxNode)CurrentNode.GetChild(index), DepthCount - 1, -Beta, -Alpha, -colour);
if (Value < ChildValue)
{
Value = ChildValue;
CurrentNode.BestChild = (StishMiniMaxNode)CurrentNode.GetChild(index);
CurrentNode.NegaMaxValue = Value;
}
Alpha = Math.Max(Alpha, Value);
if (Alpha > Beta)
{
//this return statement "prunes" the tree and prevents further growth on the tree in those bad areas
return(colour * CurrentNode.FindValue(CurrentNode, CurrentNode.NodeBoardState, CurrentNode.Allegiance));
}
}
//if the node does not need to be pruned
return(colour * CurrentNode.FindValue(CurrentNode, CurrentNode.NodeBoardState, CurrentNode.Allegiance));
}
public double TraverseTree(StishMiniMaxNode CurrentNode, int DepthCount, int colour)
{
//Depth count is given as 0 when called at root
if (CurrentNode == null || DepthCount == 0)
{
//the number 3 is a variable to be changed as sight increases
return(colour * CurrentNode.FindValue(CurrentNode, CurrentNode.NodeBoardState, CurrentNode.Allegiance));
}
double Value = double.MinValue;
double ChildValue;
for (int index = 0; index < CurrentNode.CountChildren(); index++)
{
ChildValue = -TraverseTree((StishMiniMaxNode)CurrentNode.GetChild(index), DepthCount - 1, -colour);
if (Value < ChildValue)
{
Value = ChildValue;
CurrentNode.BestChild = (StishMiniMaxNode)CurrentNode.GetChild(index);
CurrentNode.NegaMaxValue = Value;
}
}
return(Value);
}