fixed issues with MCTS and board

Author: gkcs

src/main/java/main/java/codingame/TicTacToe/TicTacToe.java

@@ -10,46 +10,59 @@ public class TicTacToe {
  public static void main(String args[]) throws IOException {
  final BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
  final LargeBoard largeBoard = new LargeBoard();
- final MCTS algorithm = new MCTS(largeBoard);
+// largeBoard.play(1, 0);
+// largeBoard.play(1, 1);
+// largeBoard.play(1, 3);
+// largeBoard.play(1, 2);
+// largeBoard.play(1, 7);
+// largeBoard.play(1, 9);
+// System.out.println(largeBoard);
+ final MCTS algorithm = new MCTS();
+ algorithm.construct(largeBoard, MCTS.TIME_OUT);
  while (true) {
  String line[] = in.readLine().split(" ");
  final int opponentRow = Integer.parseInt(line[0]), opponentCol = Integer.parseInt(line[1]);
  if (opponentCol >= 0) {
- largeBoard.play(2, opponentRow * 9 + opponentCol);
+ final int opponentMove = opponentRow * 9 + opponentCol;
+ if (algorithm.root.getChild(opponentMove) == null) {
+ algorithm.root.expand(largeBoard, opponentMove);
+ }
+ largeBoard.play(2, opponentMove);
+ algorithm.root = algorithm.root.getChild(opponentMove);
+ algorithm.construct(largeBoard, MCTS.TIME_OUT);
  System.err.println(largeBoard);
  }
  final int validActionCount = Integer.parseInt(in.readLine());
- int bRow = 0, bCol = 0;
  for (int i = 0; i < validActionCount; i++) {
- line = in.readLine().split(" ");
- bRow = Integer.parseInt(line[0]);
- bCol = Integer.parseInt(line[1]);
+ in.readLine();
  }
  final int bestMove = algorithm.suggestMove();
- final int row = bestMove / 3, col = bestMove % 3;
+ final int row = bestMove / 9, col = bestMove % 9;
+ System.out.println(row + " " + col);
  largeBoard.play(1, bestMove);
- System.out.println(((bRow / 3) * 3 + row) + " " + ((bCol / 3) * 3 + col));
+ algorithm.root = algorithm.root.getChild(bestMove);
+ algorithm.construct(largeBoard, MCTS.TIME_OUT);
  System.err.println(largeBoard);
  }
  }
 }
 
 class MCTS {
- public static final int TIME_OUT = 200;
+ public static final int TIME_OUT = 50;
  public static final double CONSTANT = 10000d;
- private final TreeNode root = new TreeNode(-1, null, 1);
+ TreeNode root = new TreeNode(-1, null, 1);
 
  public int suggestMove() {
  return root.getChildren()
  .stream()
  .max(Comparator.comparingDouble(node -> node.wins / (double) node.plays + node.plays / CONSTANT))
  .map(c -> c.col)
- .orElse(0);
+ .orElseThrow(() -> new RuntimeException("No moves to play!"));
  }
 
- public MCTS(final LargeBoard board) {
+ public void construct(final LargeBoard board, final int timeOut) {
  final long startTime = System.currentTimeMillis();
- while (System.currentTimeMillis() - startTime <= TIME_OUT) {
+ while (System.currentTimeMillis() - startTime <= timeOut) {
  TreeNode current = root;
  int position = current.selectChild(board);
  int player = 1;
@@ -111,6 +124,7 @@ private double getUtility() {
 
  private double simulate(final LargeBoard board, int player) {
  int numberOfMovesPlayed = board.movesPlayed;
+ final int originalPlayer = player;
  while (board.result() == -1) {
  final int possibilities[] = new int[81];
  int movesToPlay = 0;
@@ -120,10 +134,13 @@ private double simulate(final LargeBoard board, int player) {
  movesToPlay++;
  final int result = board.result();
  if (result != -1) {
- return result == player ? 1 : (result == 0 ? 0.5 : 0);
+ return result == originalPlayer ? 1 : (result == 0 ? 0.5 : 0);
  }
  }
  }
+ if (movesToPlay == 0) {
+ break;
+ }
  board.play(player, possibilities[random.nextInt(movesToPlay)]);
  player = player == 1 ? 2 : 1;
  }
@@ -165,21 +182,21 @@ public TreeNode getChild(final int col) {
  @Override
  public String toString() {
  return "TreeNode{" +
- "col=" + col +
- ", plays=" + plays +
- ", wins=" + wins +
- ", parent=" + (parent == null ? -1 : parent.col) +
- ", player=" + player +
- ", children=" + children.values()
+ "\ncol=" + col +
+ ", \nplays=" + plays +
+ ", \nwins=" + wins +
+ ", \nparent=" + (parent == null ? -1 : parent.col) +
+ ", \nplayer=" + player +
+ ", \nchildren=" + children.values()
  .stream()
- .map(c -> "COL: " + c.col + " WINS: " + c.wins + " PLAYS: " + c.plays + "\n")
- .collect(Collectors.joining(",")) +
+ .map(c -> "MOVE: " + c.col + " WINS: " + c.wins + " PLAYS: " + c.plays + "\n")
+ .collect(Collectors.joining("\n")) +
  '}';
  }
 }
 
 class LargeBoard {
- public static final int FULL = (1 << 10) - 1;
+ public static final int FULL = (1 << 9) - 1;
  int movesPlayed;
  int largeBoard, largeCaptures, largeOccupied;
  final int moves[] = new int[81];
@@ -197,14 +214,25 @@ public void play(final int player, final int p) {
  final int row = (p / 9) % 3, col = p % 3;
  if (movesPlayed > 0) {
  final int previousMove = moves[movesPlayed - 1];
- final int pRow = previousMove / 27, pCol = (previousMove % 9) / 3;
- assert (largeOccupied & (1 << (pRow * 3 + pCol))) != 0 || (bRow == pRow && bCol == pCol);
+ final int pMoveRow = (previousMove / 9) % 3, pMoveCol = previousMove % 3;
+ if (!((largeOccupied & (1 << (pMoveRow * 3 + pMoveCol))) != 0 || (bRow == pMoveRow && bCol == pMoveCol))) {
+ throw new RuntimeException();
+ }
  }
  final int position = bRow * 3 + bCol;
- assert (largeOccupied & (1 << position)) == 0;
+ int bit = 1 << position;
+ if ((largeOccupied & bit) != 0) {
+ throw new RuntimeException();
+ }
  boards[position].play(player, row * 3 + col);
- if (boards[position].occupied == FULL) {
- largeOccupied = largeOccupied | (1 << position);
+ if (boards[position].result(player) == player) {
+ if (player == 1) {
+ largeBoard = largeBoard | bit;
+ }
+ largeCaptures = largeCaptures | bit;
+ largeOccupied = largeOccupied | bit;
+ } else if (boards[position].occupied == FULL) {
+ largeOccupied = largeOccupied | bit;
  }
  movesPlayed++;
  }
@@ -223,22 +251,19 @@ public void undo() {
 
  public int result() {
  int firstScore = 0, secondScore = 0;
- for (int i = 0; i < 3; i++) {
- for (int j = 0; j < 3; j++) {
- final int position = i * 3 + j;
- final int bit = 1 << position;
- if (boards[position].result(1) == 1) {
- largeBoard = largeBoard | bit;
- firstScore++;
- largeCaptures = largeCaptures | bit;
- largeOccupied = largeOccupied | bit;
- } else if (boards[position].result(2) == 2) {
- secondScore++;
- largeCaptures = largeCaptures | bit;
- largeOccupied = largeOccupied | bit;
- } else if (boards[position].occupied == FULL) {
- largeOccupied = largeOccupied | bit;
- }
+ for (int position = 0; position < 9; position++) {
+ final int bit = 1 << position;
+ if (boards[position].result(1) == 1) {
+ largeBoard = largeBoard | bit;
+ firstScore++;
+ largeCaptures = largeCaptures | bit;
+ largeOccupied = largeOccupied | bit;
+ } else if (boards[position].result(2) == 2) {
+ secondScore++;
+ largeCaptures = largeCaptures | bit;
+ largeOccupied = largeOccupied | bit;
+ } else if (boards[position].occupied == FULL) {
+ largeOccupied = largeOccupied | bit;
  }
  }
  if (firstScore > 4) {
@@ -261,8 +286,8 @@ public boolean canPlay(final int p) {
  final int row = (p / 9) % 3, col = p % 3;
  if (movesPlayed > 0) {
  final int previousMove = moves[movesPlayed - 1];
- final int pRow = previousMove / 27, pCol = (previousMove % 9) / 3;
- if (!((largeOccupied & (1 << (pRow * 3 + pCol))) != 0 || (bRow == pRow && bCol == pCol))) {
+ final int pMoveRow = (previousMove / 9) % 3, pMoveCol = previousMove % 3;
+ if (!((largeOccupied & (1 << (pMoveRow * 3 + pMoveCol))) != 0 || (bRow == pMoveRow && bCol == pMoveCol))) {
  return false;
  }
  }
@@ -273,9 +298,12 @@ public boolean canPlay(final int p) {
  @Override
  public String toString() {
  return "LargeBoard{" +
- "largeBoard=" + largeBoard +
- ", largeCaptures=" + largeCaptures +
- ", boards=" + Arrays.deepToString(boards) +
+ "\nlargeBoard=" + largeBoard +
+ ", \nlargeCaptures=" + largeCaptures +
+ ", \nlargeOccupied=" + largeOccupied +
+ ", \nmovesPlayed=" + movesPlayed +
+ ", \nmoves=" + Arrays.toString(moves) +
+ ", \nboards=" + Arrays.deepToString(boards) +
  '}';
  }
 }
@@ -297,7 +325,9 @@ class Board {
 
  public void play(final int player, final int p) {
  final int bit = 1 << p;
- assert (occupied & bit) == 0;
+ if ((occupied & bit) != 0) {
+ throw new RuntimeException();
+ }
  if (player == 1) {
  board = board | bit;
  }
@@ -306,7 +336,9 @@ public void play(final int player, final int p) {
 
  public void undo(final int p) {
  final int bit = 1 << p;
- assert (occupied & bit) != 0;
+ if ((occupied & bit) == 0) {
+ throw new RuntimeException();
+ }
  board = board & (~bit);
  occupied = occupied & (~bit);
  decided = 0;
@@ -319,9 +351,15 @@ public int result(final int player) {
  public static int evaluateBoard(final int player, int board, int occupied) {
  final int boardForPlayer = player == 1 ? board : ~board;
  final int effectiveBoard = boardForPlayer & occupied;
- for (final int winningState : winningStates) {
- if (effectiveBoard >= winningState) {
- if (winningState == (effectiveBoard & winningState)) {
+ int i = 0;
+ for (; i < winningStates.length; i++) {
+ if (effectiveBoard >= winningStates[i]) {
+ break;
+ }
+ }
+ for (; i < winningStates.length; i++) {
+ if (effectiveBoard >= winningStates[i]) {
+ if (winningStates[i] == (effectiveBoard & winningStates[i])) {
  return player;
  }
  } else {
@@ -333,6 +371,6 @@ public static int evaluateBoard(final int player, int board, int occupied) {
 
  @Override
  public String toString() {
- return "Occupied:" + Integer.toBinaryString(occupied) + "\nBoard:" + Integer.toBinaryString(board);
+ return "Occupied:" + Integer.toBinaryString(occupied) + " Board:" + Integer.toBinaryString(board) + "\n";
  }
 }