public double simulate() //It simulates all the way to the end of the game, from currentNode
{ //Based on the result of the simulation(Win/lose), it return different sim value, used to judge whether its a good node or not
MCTSState simState = new MCTSState(state.currentTurn, state.drawDeck, state.discardDeck, state.humanCards, state.AICards, state.hasDrawn, state.lastDiscard, state.lastDrawDeck);
simState.stateResult = state.stateResult;
int simValue = int.MinValue;
while (simState.stateResult == MCTSState.Result.None && simState.drawDeck.Count > 0)
{
if (!simState.hasDrawn)//In Draw phase
{
simState.hasDrawn = true;
if (simState.currentTurn == Main.Turn.AI) //AI's turn
{
if (simState.discardDeck.Count > 0)
{
if (simState.AICards.NumOfCardsOfType(simState.discardDeck.GetTop().MeldType) == 2) //if drawing from discard deck can form a meld
{
simState.AICards.Add(simState.discardDeck.Pop()); //Draw from discard deck
}
else
{
simState.AICards.Add(simState.drawDeck.Pop()); //Other wise just take from draw deck
}
}
else //If no card in discard deck, draw from draw deck
{
simState.AICards.Add(simState.drawDeck.Pop());
}
if (simState.drawDeck.Count <= 0) //After draw finish, if the draw deck is empty, mark the game result as draw
{
simState.stateResult = MCTSState.Result.Draw;
break;
}
if (CardsInHand.CheckVictory(simState.AICards)) //If victory goal met, mark the game result as AIWIN
{
simState.stateResult = MCTSState.Result.AIWin;
break;
}
}
else if (simState.currentTurn == Main.Turn.Human) //Human's turn，everything same as above, basically duplicated code
{
if (simState.discardDeck.Count > 0)
{
if (simState.humanCards.NumOfCardsOfType(simState.discardDeck.GetTop().MeldType) == 2) //if drawing from discard deck can form a meld
{
simState.humanCards.Add(simState.discardDeck.Pop());
}
else
{
simState.humanCards.Add(simState.drawDeck.Pop());
}
}
else
{
simState.humanCards.Add(simState.drawDeck.Pop());
}
if (simState.drawDeck.Count <= 0)
{
simState.stateResult = MCTSState.Result.Draw;
break;
}
if (CardsInHand.CheckVictory(simState.humanCards))
{
simState.stateResult = MCTSState.Result.HumanWin;
break;
}
}
}
else if (simState.hasDrawn)//In discard phase
{
simState.hasDrawn = false;
if (simState.currentTurn == Main.Turn.AI) //AI's turn
{
MeldType typeToDiscard = MostUselessType(simState.AICards); //Get the least valuable meld type among the cards in hand
Card cardToDiscard = simState.AICards.GetCardByMeldType(typeToDiscard); //get a card of that meld type, then discard it
simState.AICards.Remove(cardToDiscard);
simState.AICards.LeftShiftElement();
simState.discardDeck.Add(cardToDiscard);
simState.discardDeck.LeftShiftElement();
simState.currentTurn = Main.Turn.Human;
}
else //duplicated code
{
MeldType typeToDiscard = MostUselessType(simState.humanCards);
Card cardToDiscard = simState.humanCards.GetCardByMeldType(typeToDiscard);
simState.humanCards.Remove(cardToDiscard);
simState.humanCards.LeftShiftElement();
simState.discardDeck.Add(cardToDiscard);
simState.discardDeck.LeftShiftElement();
simState.currentTurn = Main.Turn.AI;
}
}
}
switch (simState.stateResult)
{
case MCTSState.Result.Draw:
{
// Debug.Log("Draw result simed");
simValue = 0;
break;
}
case MCTSState.Result.HumanWin:
{
// Debug.Log("HumanWin result simed");
simValue = -1; //1 means victory, -1 means defeat
break;
}
case MCTSState.Result.AIWin:
{
//Debug.Log("AIWin result simed");
simValue = 1;
break;
}
default:
{
// Debug.LogError("illegal simStateResult value");
break;
}
}
return(simValue);
}
public TreeNode(MCTSState state)
{
this.state = state;
}