Class UCT

src/mcts/UCT.java

+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package mcts;
+
+import java.util.Collections;
+import java.util.Comparator;
+
+/**
+ *
+ * @author Lloyd
+ */
+public class UCT {
+    
+    public static double calculUCT(int nbVisiteParent, int nbVictoire, int nbVisiteEnfant, double coefficientUCT) {
+        if (nbVisiteEnfant == 0) {
+            return Integer.MAX_VALUE;
+        }
+        return ((double) nbVictoire/(double) nbVisiteEnfant + coefficientUCT *  Math.sqrt(Math.log(nbVisiteParent)/(double) nbVisiteEnfant));
+    }
+    
+    public static Noeud trouverNoeudPrometteur(Noeud noeud, double coefficient) {
+        int nbVisiteParent = noeud.getEtat().getNbVisite();
+        Noeud noeudPrometteur = null;
+        double uctNoeudPrometteur = Integer.MIN_VALUE;
+        
+        for (Noeud enfant : noeud.getListeEnfant()) {
+            int nbVictoireEnfant = enfant.getEtat().getNbVictoire();
+            int nbVisiteEnfant = enfant.getEtat().getNbVisite();
+            double valeurUCTenfant = calculUCT(nbVisiteParent, nbVictoireEnfant, nbVisiteEnfant, coefficient); 
+                    
+            if (valeurUCTenfant > uctNoeudPrometteur) {
+                uctNoeudPrometteur = valeurUCTenfant;
+                noeudPrometteur = enfant;
+            }
+        }
+        
+        return noeudPrometteur;
+    }
+    
+    
+    /* // no such element exeption
+    public static Noeud trouverMeilleurNoeud(Noeud noeud, double coefficient) {
+        int nbVisiteParent = noeud.getEtat().getNbVisite();
+        return Collections.max(
+          noeud.getListeEnfant(),
+          Comparator.comparing(c -> calculUCT(nbVisiteParent, c.getEtat().getNbVictoire(), c.getEtat().getNbVisite(), coefficient)));
+    }
+    */
+}