I'm implementing a card game in java, however i cannot expand efficiently the game tree in order for computer to execute MiniMax algorithm on it, here is the code:
public void BuildTree(Stato State,int depth)
{
if(depth < 0)
{
throw new IllegalArgumentException();
}
if(depth == 0)
{
State.Results = null;
}
if(depth > 0)
{
for(int i=0; i<depth; i++)
{
State.GeneraSuccessore();
System.out.println("SIZE: "+SizeOfTree(State));
for(Stato S : State.Results)
{
S.GeneraSuccessore();
}
}
}
DecisionTree = State;
PrintAlbero();
}
This is the structure of a State (Stato.java). Each State contains:
- Cards in the hand of the CPU
- Cards on the table
- Current CPU score
- A label
- A KnowledgeBase in order to know stats about cards such as probability and gain for each move
- A boolean indicating if its the turn of Computer (player MAX) or Player (player MIN)
public class Stato
{
/*----CONFIGURAZIONE RELATIVA AD UNO STATO----*/
KnowledgeBase Actual;
ArrayList<Carta> Table;
ArrayList<Carta> Hand;
ArrayList<Carta> Opponent;
Gioco Game;
Punteggio Score;
boolean IsMax;
String Label;
double Gain;
/*----FINE CONFIGURAZIONE RELATIVA AD UNO STATO----*/
/*----IMPLEMENTAZIONE DEI NODI PER L'USO DELLA RICORSIONE----*/
Stato Parent;
ArrayList<Stato> Results;
/*----FINE IMPLEMENTAZIONE DEI NODI PER L'USO DELLA RICORSIONE----*/
public Stato(String L,ArrayList<Carta> T,ArrayList<Carta> H,KnowledgeBase K,Punteggio S,boolean Q)
{
Actual = K;
Table = T;
Hand = H;
Label = L;
Score = S;
IsMax = Q;
Parent = null;
Gain = 0;
Results = new ArrayList();
}
public void GeneraSuccessore()
{
boolean turn = !IsMax;
if(!turn)//CASO MAX (TURNO CPU)
{
for(Carta C : Hand)
{
if(C.IsMarked() && !Table.isEmpty())
{
for(int Sc = 1; Sc <=C.Potenziale.size(); Sc++)
{
if(C.HasPotential(Sc))
{
Stato S1;
S1 = new Stato(Label+"-> "+C.nome+"/"+Sc,FT(Table,C,Sc),FH(Hand,C),FKB(Actual,C),FS(Score,C),turn);
S1.Gain = C.ValoriPotenziale.get(Sc);
Results.add(S1);
}
}
}
else
{
Stato S1;
S1 = new Stato(Label+"-> "+C.nome+"/"+0,FT(Table,C,1),FH(Hand,C),FKB(Actual,C),FS(Score,C),turn);
S1.Gain = 0.0;
Results.add(S1);
}
}
}
else//CASO MIN (TURNO GIOCATORE)
{
GetOpponent();
for(Carta C : Opponent)
{
if(C.IsMarked() && !Table.isEmpty())
{
for(int Sc = 1; Sc <=C.Potenziale.size(); Sc++)
{
if(C.HasPotential(Sc))
{
Stato S1;
S1 = new Stato(Label+"-> "+C.nome+"/"+Sc,FT(Table,C,Sc),FH(Opponent,C),FKB(Actual,C),FS(Score,C),turn);
S1.Gain = C.ValoriPotenziale.get(Sc);
Results.add(S1);
}
}
}
else
{
Stato S1;
S1 = new Stato(Label+"-> "+C.nome+"/"+0,FT(Table,C,1),FH(Opponent,C),FKB(Actual,C),FS(Score,C),turn);
S1.Gain = 0.0;
Results.add(S1);
}
}
}
}
public ArrayList<Carta> FT(ArrayList<Carta> T,Carta C,int Scelta)
{
if(C.HasPotential(Scelta))
{
ArrayList<Carta> TB = new ArrayList();
TB.addAll(T);
for(Carta C1 : C.Potenziale.get(Scelta))
{
TB.remove(C1);
}
return TB;
}
else
{
ArrayList<Carta> TB = new ArrayList();
TB.addAll(T);
TB.add(C);
return TB;
}
}
public ArrayList<Carta> FH(ArrayList<Carta> H,Carta C)
{
ArrayList<Carta> HND = new ArrayList();
HND.addAll(H);
HND.remove(C);
return HND;
}
public KnowledgeBase FKB(KnowledgeBase K,Carta C)
{
KnowledgeBase KB1 = K;
KB1.RimuoviCarta(C);
return KB1;
}
public Punteggio FS(Punteggio S,Carta C)
{
Punteggio SCR = S;
S.AddCard(C);
return SCR;
}
public void SetKB(KnowledgeBase KB)
{
Actual = KB;
}
public void SetTable(ArrayList<Carta> Tv)
{
Table = Tv;
}
public void SetHand(ArrayList<Carta> KnownHand)
{
Hand = KnownHand;
}
public KnowledgeBase GetKB()
{
return Actual;
}
public ArrayList<Carta> GetTable()
{
return Table;
}
public ArrayList<Carta> GetHand()
{
return Hand;
}
public ArrayList<Carta> GetOpponent()
{
Opponent = Actual.GetMostValuableCards(Table,Score);
return Opponent;
}
public Stato AddResult(Stato Res)
{
Res.SetParent(this);
this.Results.add(Res);
return Res;
}
public void AddResultsList(ArrayList<Stato> ListOfStates)
{
for(Stato Res : ListOfStates)
{
Res.SetParent(this);
}
Results.addAll(ListOfStates);
}
public ArrayList<Stato> GetResults()
{
return Results;
}
protected void SetParent(Stato Previous)
{
this.Parent = Previous;
}
public Stato GetParent()
{
return Parent;
}
public void SetLabel(String L)
{
Label = L;
}
public String GetLabel()
{
return Label;
}
public void SetPunteggio(Punteggio S)
{
Score = S;
}
public Punteggio GetPunteggio()
{
return Score;
}
public void ResetGain()
{
Gain = 0.0;
}
public void SetGain(Double D)
{
Gain = D;
}
public double GeiGain()
{
return Gain;
}
public void UpdateState(KnowledgeBase KB, ArrayList<Carta> Tb,ArrayList<Carta> Hnd)
{
Actual = KB;
Table = Tb;
Hand = Hnd;
}
}
The problem is that when i call the BuildTree method, JVM stops working, i think its because this way of building a game tree is quite too time and resource-consuming.
How would you solve this?
