void GenerateChildren()
{
children = new List <MCTSNode>();
foreach (Spot spot in game.AvailableSpots)
{
game.Play(spot, false, true); // make the move
children.Add(new MCTSNode(game, spot, this));
game.UndoLastMove(true); // undo that move
}
}
/// <summary>
/// Play <paramref name="game"/> randomly to the end
/// Return positive if the player to make the first move won
/// Return negative if the player to make the first move lost
/// Return 0 if the game ends in a tie
/// </summary>
/// <param name="game"></param>
/// <returns></returns>
int Simulate(GlobalGame game)
{
Player activePlayer = game.ActivePlayer();
GlobalGame copy = CopyGlobalGame(game);
while (!copy.GameOver())
{
List <Spot> moves = copy.AvailableSpots;
bool moveFound = false;
// If there's a game-winning move, play it
// This shortens simulations and makes them more realistic
foreach (Spot spot in moves)
{
copy.Play(spot, false, true);
if (copy.Winner != null)
{
moveFound = true;
break;
}
copy.UndoLastMove(true);
}
// Otherwise play a random move
if (!moveFound)
{
Spot randomSpot = moves[UnityEngine.Random.Range(0, moves.Count)];
copy.Play(randomSpot, false, true);
}
}
if (copy.Winner == activePlayer)
{
return(1);
}
if (copy.Winner == null)
{
return(0);
}
return(-1);
}