/// <summary>
/// MaxN Algorithm
/// </summary>
/// <param name="position">Root position</param>
/// <param name="player">Player to evaluate</param>
/// <param name="currentPlyDepth">Depth to evaluate at</param>
private Vector4 MaxNAlgorithm(PlySearch s)
{
if (ShouldStop())
{
return(Vector4.Zero);
}
List <PositionNode> children = board.GetNodes(s.Value, s.CurrentPlayer);
if (children.Count == 0 || s.CurrentPlyDepth == 0)
{
Vector4 baseEval = eval.Evaluate(s.Value, s.RolledDoubles ? s.CurrentPlayer : Board.NO_PLAYER);
return(Vector4.Multiply(baseEval, s.EvalWeight));
}
Nodes += children.Count;
Vector4 best = MaxNAlgorithm(s.Next(children[0]));
for (int i = 1; i < children.Count; i++)
{
Vector4 curr = MaxNAlgorithm(s.Next(children[i]));
if (curr.GetMagnitude(s.RootPlayer) > best.GetMagnitude(s.RootPlayer))
{
Best = children[i];
this.currentEvaluation = curr;
best = curr;
}
}
return(best);
}
/// <summary>
/// Gets the next target search
/// </summary>
/// <param name="current">Next Node</param>
public PlySearch Next(PositionNode current)
{
sbyte nextPlayer = board.NextPlayer(CurrentPlayer);
PlySearch next = new PlySearch(board, current, RootPlayer, nextPlayer, CurrentPlyDepth - 1);
next.NextDepth = next.CurrentPlyDepth - 1;
if (current.RolledDoubles)
{
next.NextPlayer = next.CurrentPlayer;
next.NextDepth = next.CurrentPlyDepth;
next.DoublesCount = DoublesCount + 1;
if (next.DoublesCount >= 3)
{
current.Value.RemoveFrontMarble(next.CurrentPlayer);
next.DoublesCount = 0;
next.NextPlayer = board.NextPlayer(next.CurrentPlayer);
next.NextDepth = next.CurrentPlyDepth - 1;
}
}
else
{
next.DoublesCount = 0;
}
return(next);
}
/// <summary>
/// Gets the next target search for a minimax algorithm
/// </summary>
/// <param name="current">Next node</param>
public PlySearch NextMiniMax(PositionNode current)
{
//Flipped maximizing because this is normally after we invert the bool
sbyte nextPlayer = (!Maximizing) ? board.NextPlayer(CurrentPlayer) : CurrentPlayer;
PlySearch next = new PlySearch(board, current, RootPlayer, nextPlayer, CurrentPlyDepth - 1);
next.Maximizing = !Maximizing;
next.NextDepth = next.CurrentPlyDepth - 1;
if (current.RolledDoubles)
{
next.NextPlayer = next.CurrentPlayer;
next.NextDepth = next.CurrentPlyDepth;
next.DoublesCount = DoublesCount + 1;
if (next.DoublesCount >= 3)
{
current.Value.RemoveFrontMarble(next.CurrentPlayer);
next.DoublesCount = 0;
next.NextPlayer = board.NextPlayer(next.CurrentPlayer);
next.NextDepth = next.CurrentPlyDepth - 1;
}
}
else
{
next.DoublesCount = 0;
}
return(next);
}
/// <summary>
/// Paranoid Algorithm
/// </summary>
/// <param name="position">Root position</param>
/// <param name="player">Player to evaluate</param>
/// <param name="currentPlyDepth">Depth to evaluate at</param>
public Vector4 ParanoidAlgorithm(PlySearch s, double alpha, double beta)
{
if (ShouldStop())
{
return(Vector4.Zero);
}
List <PositionNode> children = board.GetNodes(s.Value, s.CurrentPlayer);
if (children.Count == 0 || s.CurrentPlyDepth == 0)
{
Vector4 baseEval = eval.Evaluate(s.Value, s.RolledDoubles ? s.CurrentPlayer : Board.NO_PLAYER);
return(Vector4.Multiply(baseEval, s.EvalWeight));
}
Nodes += children.Count;
if (s.Maximizing)
{
Vector4 bestValue = ParanoidAlgorithm(s.NextMiniMax(children[0]), alpha, beta);
for (int i = 1; i < children.Count; i++)
{
Vector4 curr = ParanoidAlgorithm(s.NextMiniMax(children[i]), alpha, beta);
alpha = Math.Max(alpha, curr.GetMagnitude(s.RootPlayer));
if (curr.GetMagnitude(s.RootPlayer) > bestValue.GetMagnitude(s.RootPlayer))
{
bestValue = curr;
}
if (beta < alpha)
{
break;
}
}
return(bestValue);
}
else
{
Vector4 bestValue = ParanoidAlgorithm(s.NextMiniMax(children[0]), alpha, beta);
for (int i = 1; i < children.Count; i++)
{
Vector4 curr = ParanoidAlgorithm(s.NextMiniMax(children[i]), alpha, beta);
double min = curr.GetLength(s.RootPlayer);
double max = curr.GetMagnitude(s.RootPlayer);
double dif = max - min;
beta = Math.Min(beta, dif);
if (dif < bestValue.GetMagnitude(s.RootPlayer))
{
bestValue = curr;
}
if (beta < alpha)
{
break;
}
}
return(bestValue);
}
}
/// <summary>
/// Starts the initial call of the Paranoid algorithm
/// </summary>
private void Run()
{
PlySearch start = new PlySearch(board, Root, Player, board.NextPlayer(Player), Board.TEAM_COUNT * 2);
ParanoidAlgorithm(start, double.MinValue, double.MaxValue);
}
/// <summary>
/// Starts the initial call of the MaxN algorithm
/// </summary>
private void Run()
{
PlySearch search = new PlySearch(board, Root, Player, board.NextPlayer(Player), Board.TEAM_COUNT * 2); //8 Ply ahead
MaxNAlgorithm(search);
}
/// <summary>
/// Starts the initial call of the MaxN algorithm
/// </summary>
private void Run()
{
PlySearch search = new PlySearch(board, Root, Player, board.NextPlayer(Player), Board.TEAM_COUNT);
OffensiveAlgorithm(search);
}
