protected State Expand(Board Game)
{
// maybe the next move
int MoveId;
// until the game ends play it
while (Game.TestVictory() == State.empty)
{
List<int> ValidMoves = Game.GetValidMoves();
MoveId = Rnd.Next(0, ValidMoves.Count - 1);
Game.Move(ValidMoves[MoveId]);
}
// return the winner
return Game.TestVictory();
}
/// <summary>
/// internal score of move
/// </summary>
/// <param name="Situation">current game situation</param>
/// <param name="Move">move to do</param>
/// <param name="deep">current deep</param>
/// <returns>value of move</returns>
protected float ScoreMove(Board Situation, int Move, int deep)
{
// game finished?
State Result = Situation.TestVictory();
// if game is finished ...
if (Result != State.empty)
{
// is draw?
if (Result == State.draw)
return 0.0f;
// else return score 1.0f for winning and -1.0f for loosing
return (Result == Situation.CurrentPlayer) ? 1f : -1f;
}
// cut deep
if (deep == MAX_DEEP)
{
// adjust strength dynamically
int S = Convert.ToInt32(Strength / ((double)Math.Pow(7, MAX_DEEP)));
Scores.SetStrength(S);
// Score Board due monte carlo
return Scores.Evaluate(Situation, Move);
}
Situation.Move(Move); // do move
List<int> CandidateMoves = Situation.GetValidMoves(); // new situation, so new possible moves
float val = float.MinValue; // temp alpha value
foreach (int M in CandidateMoves)
{
val = Math.Max(val, -1f * ScoreMove(Situation, M, deep + 1)); // evaluate each move by recursion
}
Situation.UnMove(Move); // redo move
return val; // return value
}