improved AI

src/game/Game.java

@@ -154,13 +154,13 @@ public class Game {
 		if(output){
 		    System.out.println(other(currentP).getP().getName() + " wins.");
 		}
-		return other(currentP).getID(); // TODO this only works if the players hav IDs 1 and 2
+		return other(currentP).getID(); // TODO only works if the players have IDs 1 and 2
 	    }
         }
         // Uninstall Jansi
         AnsiConsole.systemUninstall();
         System.out.println("BUG!");
-        return checkState(false); // this is impossible to reach this, but it makes the compiler happy ;)
+        return checkState(false); // can't be reached
     }
 
     /**

src/player/maurizio/MaurizioAI.java

@@ -64,7 +64,58 @@ public class MaurizioAI implements Player {
         }
 
         //look for two move wins among the non-loosing moves
+        int m2 = winningMove2(board, id, moves1);
+        if(m2 != -1){
+            return m2;
+        }
+
+        //copy moves
+        LinkedList<Integer> moves2 = new LinkedList<Integer>();
         for(int i : moves1){
+            moves2.add(i);
+        }
+        // avoid 2-move losses
+        for(int i : moves1){ // I make a move
+            int[][] board1 = makeMove(board, i, id);
+            int m3 = winningMove2(board1, enemyID, allMoves());
+            if(m3 != -1){
+                moves2.remove((Object) i);
+            }
+        }
+
+        if(!moves2.isEmpty()){
+            return moveCentral(board, moves2);
+        } else {
+            if(!moves1.isEmpty()){
+                return moveCentral(board, moves1);
+            }
+        }
+
+        return moveCentral(board); // can't be reached
+    }
+
+    private int winningMove(int [][] board, int id){
+         for(int i=0;i<Game.GAME_COLUMNS;i++){
+            if(board[i][0] == 0 && checkWin(board, i, id)){
+                return i;
+            }
+         }
+	 return -1;// signals that no winning move exists
+    }
+
+    private LinkedList<Integer> allMoves(){
+        LinkedList<Integer> ret = new LinkedList<Integer>();
+        for(int i=0;i<Game.GAME_COLUMNS;i++){
+            ret.add(i);
+        }
+        return ret;
+    }
+
+    private int winningMove2(int[][] board, int id, LinkedList<Integer> moves){
+        for(int i : moves){
+            if(board[i][0] != 0){
+                continue;
+            }
             int[][] boardNew = makeMove(board, i, id);
             boolean winner1 = true;
             for(int j=0;j<Game.GAME_COLUMNS;j++){
@@ -81,56 +132,7 @@ public class MaurizioAI implements Player {
                 return i;
             }
         }
-
+        return -1; // no move found that wins in 2 moves
-        //copy moves
-        LinkedList<Integer> moves2 = new LinkedList<Integer>();
-        for(int i : moves1){
-            moves2.add(i);
-        }
-        // avoid 2-move losses
-        for(int i : moves1){ // I make a move
-            int[][] board1 = makeMove(board, i, id);
-            for(int j=0;j<Game.GAME_COLUMNS;j++){ // opponent makes a move
-                if(board1[j][0] != 0){
-                    continue;
-                }
-                int[][] board2 = makeMove(board1, j, enemyID);
-                for(int k=0;k<Game.GAME_COLUMNS;k++){ // I make another move
-                    if(board2[k][0] != 0){
-                        continue;
-                    }
-                    int[][] board3 = makeMove(board2, k, id);
-                    //have to make sure that no move of my opponent wins
-                    int move = winningMove(board3, enemyID);
-                    if(move != -1){
-                        moves2.remove((Object) i);
-                    }
-                }
-            }
-        }
-
-        if(!moves2.isEmpty()){
-            this.ran = new Random();
-            int choice = ran.nextInt(moves2.size());
-            return moves2.get(choice);
-        } else {
-            if(!moves1.isEmpty()){
-                this.ran = new Random();
-                int choice = ran.nextInt(moves1.size());
-                return moves1.get(choice);
-            }
-        }
-
-        return moveRandom(board); // can't be reached
-    }
-
-    private int winningMove(int [][] board,int id){
-         for(int i=0;i<Game.GAME_COLUMNS;i++){
-            if(board[i][0] == 0 && checkWin(board, i, id)){
-                return i;
-            }
-         }
-	 return -1;// signals that no winning move exists
     }
 
     private int moveRandom(int[][] board){
@@ -141,6 +143,60 @@ public class MaurizioAI implements Player {
         return choice;
     }
 
+    private int moveCentral(int[][] board){
+        if(board[3][0] == 0){
+            return 3;
+        }
+        if(board[2][0] == 0){
+            return 2;
+        }
+        if(board[4][0] == 0){
+            return 4;
+        }
+        if(board[1][0] == 0){
+            return 1;
+        }
+        if(board[5][0] == 0){
+            return 5;
+        }
+        if(board[0][0] == 0){
+            return 0;
+        }
+        if(board[6][0] == 0){
+            return 6;
+        }
+        return -1; // board is full
+    }
+
+    private int moveCentral(int[][] board, LinkedList<Integer> moves){
+        if (moves.isEmpty()) {
+            return -1; // empty list
+        }
+        if(moves.contains(3) && board[3][0] == 0){
+            return 3;
+        }
+        if(moves.contains(2) && board[2][0] == 0){
+            return 2;
+        }
+        if(moves.contains(4) && board[4][0] == 0){
+            return 4;
+        }
+        if(moves.contains(1) && board[1][0] == 0){
+            return 1;
+        }
+        if(moves.contains(5) && board[5][0] == 0){
+            return 5;
+        }
+        if(moves.contains(0) && board[0][0] == 0){
+            return 0;
+        }
+        if(moves.contains(6) && board[6][0] == 0){
+            return 6;
+        }
+
+        return -1; // Can' t happen
+    }
+
     private int[][] makeMove(int[][] board, int choice, int id) {
         // Check his choice against the current board.
         if (choice < 0 || choice > Game.GAME_COLUMNS || board[choice][0] != 0) {