Merge branch 'master' of https://github.uconn.edu/sas12028/CheckersAI

src/CheckersGameState.java

@@ -1,4 +1,4 @@
-import java . util . List ;
+import java.util.List;
 public interface CheckersGameState {
 String player ();
 List < Move > actions ();

src/CheckersGameState2.java

@@ -0,0 +1,308 @@
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class CheckersGameState2 implements CheckersGameState {
+
+  // TODO: Fix king infinite recursion
+
+  // 0 = empty
+  // 1 = black piece
+  // 2 = white piece
+  // 3 = black king
+  // 4 = white king
+  private int[] board;
+
+  // 1 = black, 2 = white
+  private int player;
+
+  public static void main(String args[]) {
+    CheckersGameState2 state = new CheckersGameState2();
+    state.printState();
+    for(int i = 0; i<100; i++){
+      List<Move> actions = state.actions();
+      if(actions.size()==0){break;}
+      for(Move move : actions) {
+        System.out.println((Move2)move+" ~~ "+((Move2)move).destination());
+      }
+      state = (CheckersGameState2)state.result(actions.get(0));
+      state.printState();
+    }
+    int[] b = new int[32];
+    b[5] = 3;
+    b[8] = 2;
+    b[16] = 2;
+    b[17] = 2;
+    b[9] = 2;
+    CheckersGameState s = new CheckersGameState2(1, b);
+    s.printState();
+    for(Move m: s.actions()){
+        System.out.println(m);
+    }
+
+  }
+
+  public CheckersGameState2(int player, int[] board) {
+    this.board = board;
+    this.player = player;
+  }
+  public CheckersGameState2(int player) {
+    board = new int[32];
+    for(int i = 0; i<32; i++) {
+      if(i<12) {
+        board[i] = 1;
+      }
+      else if(i>=20) {
+        board[i] = 2;
+      }
+      else {
+        board[i] = 0;
+      }
+    }
+    if(player == 1 || player == 2) {
+      this.player = player;
+    }
+    else {
+      this.player = 1;
+    }
+  }
+  public CheckersGameState2() {
+    this(1);
+  }
+
+  public String player () {
+    if(this.player == 1) {
+      return "black";
+    }
+    else if(this.player == 2) {
+      return "white";
+    }
+    else {
+      System.out.println("Player data is wrong.");
+      return "Error";
+    }
+  }
+
+  private int otherPlayer() {
+    return (player%2) + 1;
+  }
+
+  private boolean correctColor(int space) {
+    // returns true if piece at a space is your color
+    return space != 0 && (player == space || (player + 2) == space);
+  }
+
+  private boolean isEnemy(int piece) {
+    int other = otherPlayer();
+    return piece == other || (other + 2) == piece;
+  }
+
+  private int[] neighbors(int index) {
+    int[] neighbors = new int[4];
+    int row = (index - index%4)/4;
+    int col = index%4;
+    if (row % 2 == 0) {
+      neighbors[0] = index + 4;
+      neighbors[1] = index + 5;
+      neighbors[2] = index - 4;
+      neighbors[3] = index - 3;
+
+      if(col == 3) {
+        neighbors[1] = -1;
+        neighbors[3] = -1;
+      }
+    }
+    else {
+      neighbors[0] = index + 3;
+      neighbors[1] = index + 4;
+      neighbors[2] = index - 5;
+      neighbors[3] = index - 4;
+
+      if(col == 0) {
+        neighbors[0] = -1;
+        neighbors[2] = -1;
+      }
+    }
+
+    for(int i = 0; i<4; i++) {
+      if(neighbors[i] < 0 || neighbors[i] >=32) {
+        neighbors[i] = -1;
+      }
+    }
+
+    return neighbors;
+  }
+
+  private ArrayList<Move> findJumpMoves(int starting, int current, int[] path) {
+    ArrayList<Move> moves = new ArrayList<Move>();
+    int piece = board[starting];
+    board[starting] = 0;
+    int[] neighbors = neighbors(current);
+    int beg, end;
+    if(piece == 1) {
+      beg = 0;
+      end = 2;
+    }
+    else if(piece == 2) {
+      beg = 2;
+      end = 4;
+    }
+    else {
+      beg = 0;
+      end = 4;
+    }
+    for(int i = beg; i<end; i++) {
+      boolean valid = neighbors[i] != -1 && isEnemy(board[neighbors[i]]);
+      if(valid && !isCaptured(neighbors[i], path)) {
+        int next = neighbors(neighbors[i])[i];
+        if(next != -1 && board[next] == 0) {
+          int [] newPath = Arrays.copyOf(path, path.length+1);
+          newPath[path.length] = next;
+          ArrayList<Move> jumpMoves = findJumpMoves(starting, next, newPath);
+          if(jumpMoves.size() == 0){
+            moves.add(new Move2(newPath));
+          } else {
+            moves.addAll(jumpMoves);
+          }
+        }
+      }
+    }
+    board[starting] = piece;
+    return moves;
+  }
+
+  private boolean isCaptured(int space, int[] path) {
+    Move temp = new Move2(path);
+    int[] captured = temp.captures();
+    for(int i = 0; i<captured.length; i++) {
+      if(captured[i]==space) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  private ArrayList<Move> captures() {
+    ArrayList<Move> captures = new ArrayList<Move>();
+    for(int i = 0; i<32; i++) {
+      int piece = board[i];
+      if(piece != 0 && correctColor(piece)) {
+        captures.addAll(findJumpMoves(i, i, new int[]{i}));
+      }
+    }
+    return captures;
+  }
+
+  private ArrayList<Move> noncaptures() {
+    ArrayList<Move> moves = new ArrayList<Move>();
+    for(int i = 0; i<32; i++) {
+      int space = board[i];
+      if(space != 0 && correctColor(space)) {
+        int[] neighbors = neighbors(i);
+        if(space == 1) {
+          // black piece
+          if(neighbors[0] != -1 && board[neighbors[0]] == 0) {
+            moves.add(new Move2(i, neighbors[0]));
+          }
+          if(neighbors[1] != -1 && board[neighbors[1]] == 0) {
+            moves.add(new Move2(i, neighbors[1]));
+          }
+        }
+        else if(space == 2) {
+          // white piece
+          if(neighbors[2] != -1 && board[neighbors[2]] == 0) {
+            moves.add(new Move2(i, neighbors[2]));
+          }
+          if(neighbors[3] != -1 && board[neighbors[3]] == 0) {
+            moves.add(new Move2(i, neighbors[3]));
+          }
+        }
+        else {
+          // king
+          for(int j = 0; j<4; j++) {
+            if(neighbors[j] != -1 && board[neighbors[j]] == 0) {
+              moves.add(new Move2(i, neighbors[j]));
+            }
+          }
+        }
+      }
+    }
+    return moves;
+  }
+
+  public List <Move> actions() {
+    ArrayList<Move> actions = this.captures();
+    if(actions.size() != 0) {
+      return actions;
+    }
+    else {
+      actions = this.noncaptures();
+    }
+    return actions;
+  }
+
+  public CheckersGameState result ( Move x ) {
+    Move2 move = (Move2) x;
+    int[] newBoard = Arrays.copyOf(board, board.length);
+    int newPlayer = otherPlayer();
+    int[] captures = move.captures();
+    if(captures[0] != -1) {
+      for(int i = 0; i<captures.length; i++) {
+        newBoard[captures[i]] = 0;
+      }
+    }
+    newBoard[move.destination()] = newBoard[move.source()];
+    newBoard[move.source()] = 0;
+
+    if(promote(move.source(), move.destination())) {
+      newBoard[move.destination()] += 2;
+    }
+
+    return new CheckersGameState2(newPlayer, newBoard);
+  }
+
+  private boolean promote(int src, int dest) {
+    switch(board[src]) {
+      case 0:
+        return false;
+      case 1:
+        return dest>=28;
+      case 2:
+        return dest<=3;
+      case 3: case 4:
+        return false;
+    }
+    return false;
+  }
+
+  public void printState () {
+    String output = "";
+    for(int i = 0; i<32; i++) {
+      int space = board[i];
+      int row = (i - i%4)/4;
+      if(i%4 == 0 && i != 0){
+        output += "\n";
+      }
+      if(row % 2 == 0) {
+        output += " - ";
+      }
+      switch (space) {
+        case 0: output += " - ";
+          break;
+        case 1: output += " b ";
+          break;
+        case 2: output += " w ";
+          break;
+        case 3: output += " B ";
+          break;
+        case 4: output += " W ";
+          break;
+      }
+
+      if(row % 2 == 1) {
+        output += " - ";
+      }
+    }
+    System.out.println(output);
+  }
+}

src/CheckersGameState3.java

@@ -240,7 +240,16 @@ public class CheckersGameState3 implements CheckersGameState{
                 newState[k] = 0;
             }
         }
-        return new CheckersGameState3(1 - this.player, newState);
+        return new CheckersGameState3(other(this.player), newState);
+    }
+
+    private int other(int player){
+        if(player == 1){
+            return 2;
+        }
+        else{
+            return 1;
+        }
     }
 
    public void printState(){