DEV: A first semi-working version with tree

GameLog.txt

@@ -80,3 +80,31 @@ Team 0.00	Mine	1	Team 0.00	Mine	0	77
 Team 0.00	Mine	1	Team 0.00	Mine	0	77
 Team 0.00	Mine	1	Team 0.00	Mine	0	94
 Team 0.00	Mine	1	Team 0.00	Mine	0	94
+Team 0.00	Mine	0	Team 0.00	Mine	1	61
+Team 0.00	Mine	0	Team 0.00	Mine	1	14
+Team 0.00	Mine	0	Team 0.00	Mine	1	4
+Team 0.00	Mine	0	Team 0.00	Mine	1	12
+Team 0.00	Mine	1	Team 0.00	Mine	0	97
+Team 0.00	Mine	1	Team 0.00	Mine	0	97
+Team 0.00	Mine	0	Team 0.00	Mine	1	22
+Team 0.00	Mine	0	Team 0.00	Mine	1	22
+Team 0.00	Mine	1	Team 0.00	Mine	0	104
+Team 0.00	Mine	0	Team 0.00	Mine	1	7
+Team 0.00	Mine	0	Team 0.00	Mine	1	7
+Team 0.00	Mine	1	Team 0.00	Mine	0	64
+Team 0.00	Mine	1	Team 0.00	Mine	0	64
+Team 0.00	Mine	1	Team 0.00	Mine	0	67
+Team 0.00	Mine	1	Team 0.00	Mine	0	67
+Team 0.00	Mine	1	Team 0.00	Mine	0	63
+Team 0.00	Mine	1	Team 0.00	Mine	0	63
+Team 0.00	Mine	1	Team 0.00	Mine	0	65
+Team 0.00	Mine	1	Team 0.00	Mine	0	65
+Team 0.00	Mine	1	Team 0.00	Mine	0	79
+Team 0.00	Mine	1	Team 0.00	Mine	0	79
+Team 0.00	Mine	1	Team 0.00	Mine	0	61
+Team 0.00	Mine	1	Team 0.00	Mine	0	61
+Team 0.00	Mine	1	Team 0.00	Mine	0	80
+Team 0.00	Mine	1	Team 0.00	Mine	0	80
+Team 0.00	Mine	1	Team 0.00	Mine	0	78
+Team 0.00	Mine	1	Team 0.00	Mine	0	71
+Team 0.00	Mine	1	Team 0.00	Mine	0	71

src/gr/auth/ee/dsproject/node/Globals.java

@@ -10,6 +10,8 @@
 
 package gr.auth.ee.dsproject.node;
 
+import gr.auth.ee.dsproject.pacman.PacmanUtilities;
+
 /**
  * @class   Globals
  * @brief
@@ -69,5 +71,5 @@ public class Globals {
    
    public static final int[] FALSE_POS = {-1, -1};
    
-   public static final int MAX_DISTANCE = 100;
+   public static final int MAX_DISTANCE = PacmanUtilities.numberOfRows + PacmanUtilities.numberOfColumns - 1;
 }

src/gr/auth/ee/dsproject/node/MinMaxTree.java

@@ -1,115 +0,0 @@
-/**
- * @file MinMaxTree.java
- * @brief
- *    File containing the Pacman Min-Max Tree class.
- * 
- * @author  Christos Choutouridis   8997 cchoutou@ece.auth.gr
- * @author  Konstantina Tsechelidou 8445 konstsec@ece.auth.gr
- */
-package gr.auth.ee.dsproject.node;
-
-/**
- * @brief
- *    A tree-like data structure containing move nodes to apply the min-max
- *    algorithm.
- * @note
- *    This is NOT a real tree. We do not insert node based on a key etc...
- */
-public class MinMaxTree
-{
-   private Node89978445 root;
-   
-   /*
-    * ============ Constructors ==============
-    */
-   /**
-    * @brief
-    *    The simple constructor. Just initialize the root to null
-    */
-   public MinMaxTree () {
-      root = null;   // No root yet
-   }
-
-   /**
-    * @brief
-    *    A constructor with root
-    */
-   public MinMaxTree (Node89978445 root) {
-      setRoot (root);
-   }
-
-   /*
-    * ========= setter ============
-    */
-   /** Set root */
-   public Node89978445 setRoot (Node89978445 root) {
-      return this.root = root;
-   }
-
-   /*
-    * ========== Tree-like methods =============
-    */
-   /**
-    * @brief
-    *    Insert a node to a parent directly.
-    *    This is NOT a real tree. We do not insert node based on a key
-    * @param node    Node to insert
-    * @param parent  The parent in witch to insert
-    * @return        Reference to inserted node
-    *                If insert fail, returns null
-    */
-   public static Node89978445 insert (Node89978445 node, Node89978445 parent) {
-      if (parent.children.add (node)) {
-         node.parent = parent;
-         return node;
-      }
-      else
-         return null;
-   }
-
-   /**
-    * @brief
-    *    Find the child with the minimum evaluation value of a
-    *    specific parent and return a reference to it
-    * @param parent  The parent of children we scan
-    * @return        Reference to the child with the minimum evaluation value
-    *                If parent has no children null.
-    */
-   public static Node89978445 minChild (Node89978445 parent)
-   {
-      Node89978445 node = null;
-      double ev, min = Globals.EVAL_MAX+1;
-
-      for (int i=0 ; i<parent.children.size() ; ++i) {
-         if ((ev = parent.children.get(i).getEvaluation()) < min) {
-            min = ev;
-            node = parent.children.get (i);
-         }
-      }
-      return node;
-   }
-
-   /**
-    * @brief
-    *    Find the child with the maximum evaluation value of a
-    *    specific parent and return a reference to it
-    * @param parent  The parent of children we scan
-    * @return        Reference to the child with the maximum evaluation value
-    *                If parent has no children null.
-    */
-   public static Node89978445 maxChild (Node89978445 parent)
-   {
-      Node89978445 node = null;
-      double ev, max = Globals.EVAL_MIN-1;
-
-      for (int i=0 ; i<parent.children.size() ; ++i) {
-         if ((ev = parent.children.get(i).getEvaluation()) > max) {
-            max = ev;
-            node = parent.children.get (i);
-         }
-      }
-      return node;
-   }
-
-   
-}

src/gr/auth/ee/dsproject/node/Node89978445.java

@@ -25,18 +25,16 @@ import gr.auth.ee.dsproject.pacman.Room;
  */
 public class Node89978445
 {
-   double nodeEvaluation;  /**<
+   double nodeEvaluation;     /*<
-                            * Pacman's current move evaluation
+                               * Pacman's current move evaluation
-                            * This is used also as the "return status" of the object
+                               * This is used also as the "return status" of the object
-                            */
+                               */
-   int[] nodeXY;                 // Pacman's current x,y coordinate
+   int[] nodeXY;              // Pacman's current x,y coordinate
-   int[][] currentGhostPos;      // Array holding the Ghost (x,y) pairs
+   int[][] curGhostPos;       // Array holding the Ghost (x,y) pairs
    
-   
+   int[][] flagPos;           // Array holding the flag (x,y) pairs
-   
+   boolean[] curFlagStatus;   // Array holding the flag capture status
-   int[][] flagPos;              // Array holding the flag (x,y) pairs
+   Room[][] Maze;             // copy of the current Maze
-   boolean[] currentFlagStatus;  // Array holding the flag capture status
-   Room[][] Maze;                // copy of the current Maze
 
    /*
     * Tree navigation references. These variables are handled by
@@ -65,10 +63,10 @@ public class Node89978445
       parent = null;
 
       // allocate objects
-      currentGhostPos = new int [PacmanUtilities.numberOfGhosts][2];
+      curGhostPos    = new int [PacmanUtilities.numberOfGhosts][2];
-      flagPos = new int [PacmanUtilities.numberOfFlags][2];
+      flagPos        = new int [PacmanUtilities.numberOfFlags][2];
-      currentFlagStatus = new boolean[PacmanUtilities.numberOfFlags];
+      curFlagStatus  = new boolean[PacmanUtilities.numberOfFlags];
-      children = new ArrayList<Node89978445> ();
+      children       = new ArrayList<Node89978445> ();
    }
 
    /**
@@ -85,10 +83,18 @@ public class Node89978445
       parent = null;
 
       // allocate objects
-      currentGhostPos = new int [PacmanUtilities.numberOfGhosts][2];
+      curGhostPos    = new int [PacmanUtilities.numberOfGhosts][2];
-      flagPos = new int [PacmanUtilities.numberOfFlags][2];
+      flagPos        = new int [PacmanUtilities.numberOfFlags][2];
-      currentFlagStatus = new boolean[PacmanUtilities.numberOfFlags];
+      curFlagStatus  = new boolean[PacmanUtilities.numberOfFlags];
-      children = new ArrayList<Node89978445> ();
+      children       = new ArrayList<Node89978445> ();
+      
+      // calculate helper arrays
+      curGhostPos    = findGhosts ();
+      flagPos        = findFlags ();
+      curFlagStatus  = checkFlags ();
+      
+      //Evaluate the position
+      nodeEvaluation = evaluate ();
    }
 
    /*
@@ -123,10 +129,15 @@ public class Node89978445
    {
       // If already evaluated do not re-evaluate the move
       if (nodeEvaluation == Globals.NO_EVAL) {
+         // Safety filters
+         if (Maze == null)
+            return Globals.NO_EVAL;
+         if (nodeXY == Globals.FALSE_POS)
+            return Globals.NO_EVAL;
          // calculate helper arrays
-         currentGhostPos = findGhosts ();
+         curGhostPos = findGhosts ();
          flagPos = findFlags ();
-         currentFlagStatus = checkFlags ();
+         curFlagStatus = checkFlags ();
          
          return nodeEvaluation = evaluate ();
       }
@@ -134,16 +145,30 @@ public class Node89978445
          return nodeEvaluation;
     }
 
-   public int[] getCurentPacmanPos () {
+   public int[] getCurrentPacmanPos () {
       return nodeXY;
    }
    public int[][] getCurrentGhostPos () {
-      return currentGhostPos;
+      return curGhostPos;
+   }
+   public int getDepth () {
+      return depth;
    }
 
    /*
     * ============= Helper API ============
     */
+   public static int moveConv (int[] nextPos, int[] curPos)
+   {
+      int dx = nextPos[0] - curPos[0];
+      int dy = nextPos[1] - curPos[1];
+           
+      if      (dx < 0)  return Room.NORTH;
+      else if (dx > 0)  return Room.SOUTH;
+      else if (dy < 0)  return Room.WEST;
+      else              return Room.EAST;
+   }
+
    /**
     * @param creature   creature's (x,y)
     * @return
@@ -273,9 +298,17 @@ public class Node89978445
    }
 
    /*
-    * ============ evaluation helper methods ==============
+    * ============ private evaluation helper methods ==============
     */
    
+   private enum Creature {
+      GHOST, PACMAN
+   }
+
+   /**
+    * @brief
+    *    Check if the requested ghost move is valid
+    */
    private int[] ghostValidMove (int[] ghost, int move)
    {
       int[] newPos = new int[2];
@@ -299,7 +332,7 @@ public class Node89978445
 
    /**
     * @brief
-    *    Check if the requested move is valid
+    *    Check if the requested pacman move is valid
     */
    private int[] pacmanValidMove (int[] pacman, int move)
    {
@@ -328,12 +361,14 @@ public class Node89978445
    /**
     * @brief
     *    A Breadth-first search to find the shortest path distance
-    *    from a ghost to a point in the maze
+    *    from an origin point to another point in the maze as if a
-    * @param ghost   Ghost (x, y)
+    *    a creature could walk through
-    * @param xy      The x, y coordinate in Maze
+    * @param origin     origin (x, y)
-    * @return
+    * @param xy         The x, y coordinate in Maze
+    * @param creature   The type of creature for whom the path is for
+    * @return           The number of steps from origin to xy
     */
-   private int ghostMoveDist (int[] ghost, int[] xy)
+   private int moveDist (int[] origin, int[] xy, Creature creature)
    {
       int move;
       int steps, qStepItems;  // distance and group counters
@@ -342,10 +377,10 @@ public class Node89978445
       int c = PacmanUtilities.numberOfColumns;  // helper for shorting names
       int[] xyItem = new int [2];   // Coordinates of the current position of the algo
       int[] xyNext = new int [2];   // Coordinates of the next valid position of the algo
-      Queue2D q = new Queue2D (r+c - 1);  // Queue to feed with possible position
+      Queue2D q = new Queue2D (Globals.MAX_DISTANCE - 1);  // Queue to feed with possible position
       int [][] dist = new int [r][c];
       /*<
-       * 2D array holding all the distances from the ghost to each square of the maze
+       * 2D array holding all the distances from the origin to each square of the maze
        */
 
       // If target square is inside a box abort with max distance
@@ -362,8 +397,8 @@ public class Node89978445
          }
       }
       // loop data
-      dist [ghost[0]][ghost[1]] = 0;   //starting point is the ghost position
+      dist [origin[0]][origin[1]] = 0;   //starting point is the origin position
-      q.insert (ghost);                // feed first loop data
+      q.insert (origin);                // feed first loop data
       qStepItems = 1;                  // init counters
       steps = 1;
       /*
@@ -380,94 +415,12 @@ public class Node89978445
             --qStepItems;              // mark the removal of the item
             for (move=0 ; move<4 ; ++move) {
                // loop every valid next position for the current position
-               if ((xyNext = ghostValidMove (xyItem, move)) != Globals.FALSE_POS) {
+               switch (creature) {
-                  if (dist[xyNext[0]][xyNext[1]] == -1) {
+                  case GHOST:    xyNext = ghostValidMove (xyItem, move);   break;
-                     // If we haven't been there
+                  case PACMAN:   xyNext = pacmanValidMove (xyItem, move);  break;
-                     dist[xyNext[0]][xyNext[1]] = steps; // mark the distance
+                  default:       xyNext = Globals.FALSE_POS;
-                     if ((xyNext[0] == xy[0]) && (xyNext[1] == xy[1])) {
-                        /*
-                         *  first match:
-                         *  The first time we reach destination we have count the
-                         *  distance. No need any other try
-                         */
-                        done = true;
-                        break;
-                     }
-                     else {
-                        // If we are not there yet, feed queue with another position
-                        q.insert (xyNext);
-                     }
-                  }
                }
-            }
+               if (xyNext != Globals.FALSE_POS) {
-         }
-         else {
-            // We are done with group, mark how many are for the next one
-            if ((qStepItems = q.size()) <= 0)
-               return dist[xy[0]][xy[1]];    // fail safe return
-            ++steps;                         // Update distance counter
-         }
-      }
-      return dist[xy[0]][xy[1]];
-   }
-
-   /**
-    * @brief
-    *    A Breadth-first search to find the shortest path distance
-    *    from the pacman to a point in the maze. The point will normaly
-    *    represent a flag
-    * @param pacman  Pacman's (x, y)
-    * @param xy      The x, y coordinate in Maze
-    * @return
-    */
-   private int pacmanMoveDist (int[] pacman, int[] xy)
-   {
-      int move;
-      int steps, qStepItems;  // distance and group counters
-      boolean done = false;   // algo ending flag
-      int r = PacmanUtilities.numberOfRows;     // helper for shorting names
-      int c = PacmanUtilities.numberOfColumns;  // helper for shorting names
-      int[] xyItem = new int [2];   // Coordinates of the current position of the algo
-      int[] xyNext = new int [2];   // Coordinates of the next valid position of the algo
-      Queue2D q = new Queue2D (r+c - 1);  // Queue to feed with possible position
-      int [][] dist = new int [r][c];
-      /*
-       * 2D array holding all the distances from pacman to each square of the maze
-       */
-
-      // If target square is inside a box abort with max distance
-      if (isInsideBox (xy))
-         return Globals.MAX_DISTANCE;
-
-      /*
-       *  init data for algorithm
-       */
-      for (int i=0 ; i<r ; ++i) {
-         for (int j=0 ; j<c ; ++j) {
-            dist[i][j] = -1;
-            // dist array starts with -1
-         }
-      }
-      // loop data
-      dist [pacman[0]][pacman[1]] = 0; //starting point is the pacman position
-      q.insert (pacman);               // feed first loop data
-      qStepItems = 1;                  // init counters
-      steps = 1;
-      /*
-       *          Main loop of the algorithm
-       * 
-       * For every position we check the valid moves, we apply to them
-       * the step number and we push them to queue. We group the items in
-       * queue with their step number by measuring how many we push them for
-       * the current steps variable value.
-       */
-      while (done == false) {
-         if (qStepItems>0) {           // Have we any item on the current group?
-            xyItem = q.remove ();      //load an item of the current group
-            --qStepItems;              // mark the removal of the item
-            for (move=0 ; move<4 ; ++move) {
-               // loop every valid next position for the current position
-               if ((xyNext = pacmanValidMove (xyItem, move)) != Globals.FALSE_POS) {
                   if (dist[xyNext[0]][xyNext[1]] == -1) {
                      // If we haven't been there
                      dist[xyNext[0]][xyNext[1]] = steps; // mark the distance
@@ -515,7 +468,7 @@ public class Node89978445
 
       // Find ghost distances, min and average
       for (i=0, averGhostDist=0 ; i<PacmanUtilities.numberOfGhosts ; ++i) {
-         ghostDist [i] = ghostMoveDist (currentGhostPos[i], nodeXY);
+         ghostDist [i] = moveDist (curGhostPos[i], nodeXY, Creature.GHOST);
          averGhostDist += ghostDist [i];
          if (minGhostDist > ghostDist[i])
             minGhostDist = ghostDist[i];
@@ -528,8 +481,8 @@ public class Node89978445
 
       // Find flag distances and min
       for (i=0 ; i<PacmanUtilities.numberOfFlags ; ++i) {
-         if (currentFlagStatus[i] == false) {
+         if (curFlagStatus[i] == false) {
-            flagDist[i] = pacmanMoveDist (nodeXY, flagPos[i]);
+            flagDist[i] = moveDist (nodeXY, flagPos[i], Creature.PACMAN);
             if (minFlagDist > flagDist[i])
                minFlagDist = flagDist[i];
          }

src/gr/auth/ee/dsproject/node/Tree.java

@@ -0,0 +1,100 @@
+/**
+ * @file MinMaxTree.java
+ * @brief
+ *    File containing the Pacman Min-Max Tree class.
+ * 
+ * @author  Christos Choutouridis   8997 cchoutou@ece.auth.gr
+ * @author  Konstantina Tsechelidou 8445 konstsec@ece.auth.gr
+ */
+package gr.auth.ee.dsproject.node;
+
+
+/**
+ * @brief
+ *    A tree-like data structure containing move nodes to apply the min-max
+ *    algorithm.
+ * @note
+ *    This is NOT a real tree. We do not insert node based on a key etc...
+ */
+public class Tree
+{
+   /*
+    * ============ Constructor ==============
+    */
+   /**
+    * @brief
+    *    The simple constructor. Do nothing (this is a static class)
+    */
+   public Tree () { }
+
+   /*
+    * ========== private helpers  ==============
+    */
+   private static double min (double x, double y) {
+      return (x < y) ? x : y;
+   }
+   private static double max (double x, double y) {
+      return (x > y) ? x : y;
+   }
+
+   /*
+    * ========== Tree-like public methods =============
+    */
+   /**
+    * @brief
+    *    Insert a node to a parent directly.
+    *    This is NOT a real tree. We do not insert node based on a key
+    * @param node    Node to insert
+    * @param parent  The parent in witch to insert
+    * @return        Reference to inserted node
+    *                If insert fail, returns null
+    */
+   public static Node89978445 grow (Node89978445 node, Node89978445 parent) {
+      if (parent.children.add (node)) {
+         node.parent = parent;
+         node.depth = parent.depth + 1;
+         return node;
+      }
+      else
+         return null;
+   }
+
+   public static Node89978445 minmaxAB (Node89978445 node, int depth, double a, double b, boolean maxingPlayer)
+   {
+      double v, ev;
+      Node89978445 vNode = null;
+
+      if ((depth == 0) || (node.children.isEmpty()))
+         return node;
+      
+      if (maxingPlayer) {
+         v = Globals.EVAL_MIN - 1;
+         for (int i=0 ; i<node.children.size() ; ++i) {
+            ev = minmaxAB (node.children.get (i), depth-1, a, b, false).getEvaluation();
+            if (ev > v) {
+               v = ev;
+               vNode = node.children.get (i);
+            }
+            a = max (v, a);
+            if (b <= a)
+               break;
+         }
+         return vNode;
+      }
+      else {
+         v = Globals.EVAL_MAX + 1;
+         for (int i=0 ; i<node.children.size() ; ++i) {
+            ev = minmaxAB(node.children.get (i), depth-1, a, b, true).getEvaluation();
+            if (ev < v) {
+               v = ev;
+               vNode = node.children.get (i);
+            }
+            b = min (v, b);
+            if (b <= a)
+               break;
+         }
+         return vNode;
+      }
+   }
+   
+}

src/gr/auth/ee/dsproject/pacman/Creature.java

@@ -3,7 +3,7 @@ package gr.auth.ee.dsproject.pacman;
 import java.util.ArrayList;
 
 import gr.auth.ee.dsproject.node.Globals;
-import gr.auth.ee.dsproject.node.MinMaxTree;
+import gr.auth.ee.dsproject.node.Tree;
 import gr.auth.ee.dsproject.node.Node89978445;
 
 /**
@@ -38,33 +38,42 @@ public class Creature implements gr.auth.ee.dsproject.pacman.AbstractCreature
   private int step = 1;
   private boolean amPrey;
 
-  public Creature (boolean isPrey)
+  public Creature (boolean isPrey) {
-  {
     amPrey = isPrey;
-
   }
 
   /**
-   * @brief
+   * 
-   *    Create node for each one of the possible moves (0, 1, 2, 3) and
-   *    evaluate these moves.
    */
    public int calculateNextPacmanPosition (Room[][] Maze, int[] currPosition)
    {
-      Node89978445 cur = new Node89978445 (Maze, currPosition);
+      int [] bestPos = {-1, -1};    // Best position in maze to play
-      MinMaxTree mmTree = new MinMaxTree (cur);    /*<
+      Node89978445 bestNode;        // The node with the best evaluation
-                                                    * Plant a tree with dummy root
+      Node89978445 cur = new Node89978445 (Maze, currPosition);   // The node with the current position
-                                                    * Null parent and no evaluation
-                                                    */
 
-      createSubTreePacman (0, cur, Maze, currPosition);  //make the tree
+      //make the tree
-      // min-max
+      createSubTreePacman (cur.getDepth (), cur, Maze, currPosition);
-      return 0;
+
+      // min-max to find best node and consequently the best position
+      bestNode = Tree.minmaxAB (cur, Globals.MINMAXTREE_MAX_DEPTH-1, Globals.EVAL_MIN - 1, Globals.EVAL_MAX + 1, true);
+      bestPos = bestNode.getCurrentPacmanPos();
+
+      // convert back to move encoding
+      return Node89978445.moveConv (bestPos, currPosition);
    }
 
+   /**
+    * 
+    */
    void createSubTreePacman (int depth, Node89978445 parent, Room[][] Maze, int[] curPacmanPosition)
    {
-      if (++depth > Globals.MINMAXTREE_MAX_DEPTH)
+      if (depth >= Globals.MINMAXTREE_MAX_DEPTH-1)
+         /*<
+          * As the depth starts from 0 and MINMAXTREE_MAX_DEPTH
+          * is strictly even, with this comparison we accept that there
+          * is no need for a max-depth layer of ghosts-evaluation based nodes.
+          * As soon as we accept the depth-1 layers max evaluated node.
+          */
          return;
       else {
          Node89978445 newNode;
@@ -76,23 +85,31 @@ public class Creature implements gr.auth.ee.dsproject.pacman.AbstractCreature
             if ((nextPosition = Node89978445.pacmanValidMove (parent, move)) != Globals.FALSE_POS) {
                // Make a copy of the maze in order to simulate next move and move Pacman
                newMaze = PacmanUtilities.copy (Maze);
-               PacmanUtilities.movePacman (newMaze, parent.getCurentPacmanPos(), nextPosition);
+               PacmanUtilities.movePacman (newMaze, parent.getCurrentPacmanPos(), nextPosition);
          
                // Create a node for the move in the new stated game maze
                newNode = new Node89978445 (newMaze, nextPosition);
-               newNode.getEvaluation();
+               Tree.grow (newNode, parent);   // add node to the min-max tree
-               MinMaxTree.insert (newNode, parent);   // add node to the min-max tree
 
                // call the recursive ranch creator
-               createSubTreeGhosts (depth, newNode, newMaze, newNode.getCurrentGhostPos());
+               createSubTreeGhosts (newNode.getDepth (), newNode, newMaze, newNode.getCurrentGhostPos());
             }
          }
       }
    }
 
+   /**
+    * 
+    */
    void createSubTreeGhosts (int depth, Node89978445 parent, Room[][] Maze, int[][] currGhostsPosition)
    {
-      if (++depth > Globals.MINMAXTREE_MAX_DEPTH)
+      if (depth >= Globals.MINMAXTREE_MAX_DEPTH-1)
+         /*<
+          * As the depth starts from 0 and MINMAXTREE_MAX_DEPTH
+          * is strictly even, with this comparison we accept that there
+          * is no need for a max-depth layer of ghosts-evaluation based nodes.
+          * As soon as we accept the depth-1 layers max evaluated node.
+          */
          return;
       else {
          Node89978445 newNode;
@@ -103,19 +120,17 @@ public class Creature implements gr.auth.ee.dsproject.pacman.AbstractCreature
          ghostMoves = PacmanUtilities.allGhostMoves(Maze, currGhostsPosition);
 
          // loop all ghost moves
-         int s = ghostMoves.size();
+         for (int i=0 ; i<ghostMoves.size() ; ++i) {
-         for (int i=0 ; i<s ; ++i) {
             // Make a copy of the maze in order to simulate next move and move ghosts
             newMaze = PacmanUtilities.copy (Maze);
             PacmanUtilities.moveGhosts(newMaze, currGhostsPosition, ghostMoves.get(i));
             
             // Create a node for the move in the new stated game maze
-            newNode = new Node89978445 (newMaze, parent.getCurentPacmanPos());
+            newNode = new Node89978445 (newMaze, parent.getCurrentPacmanPos());
-            newNode.getEvaluation();
+            Tree.grow (newNode, parent);   // add node to the min-max tree
-            MinMaxTree.insert (newNode, parent);   // add node to the min-max tree
 
             //recursive call for the rest of the tree
-            //createSubTreePacman (depth, newNode, newMaze, parent.getCurentPacmanPos());
+            createSubTreePacman (newNode.getDepth (), newNode, newMaze, parent.getCurrentPacmanPos());
          }
       }
    }