示例#1
0
  private Board solve_dfs(Board b, int depthLimit, int depth) {
    if (depth >= depthLimit) { // Cutoff test
      return b;
    }

    Board best = null;
    int best_score = -1;

    for (int i = 0; i < BOARD_WIDTH; i++) {
      Board next = new Board(b);
      if (next.move(tileSequence, directions[i])) {
        Board candidate = solve_dfs(next, depthLimit, depth + 1);
        if (candidate == null && next.finished()) {
          candidate = next;
        }
        if (candidate != null) {
          if (candidate.finished()) {
            updateBest(candidate);
          } else {
            int score = evaluate(candidate);
            if (score > best_score) {
              best_score = score;
              best = candidate;
            }
          }
        }
      }
    }
    return best;
  }
示例#2
0
  /**
   * Single threaded depth-limited depth first search, with no backtracking.
   *
   * @param s The tile sequence
   * @param b The board to search
   * @return The final best board state that it can find.
   */
  private Board solve_ldfs(Board b) {
    Board input = b;
    fbest_score = -1;
    fbest = null;
    currentfactors = factors;
    while (b != null && !b.finished()) {
      b = solve_dfs(b, MAX_DEPTH, 0);
      if (b != null) {
        log_info(b);
      }
    }

    // Super edge-case: The input board can't be moved...
    return fbest == null ? input : fbest;
  }
示例#3
0
  /**
   * Multi-threaded depth-limited depth first search, with no backtracking.
   *
   * @param s The tile sequence
   * @param b The board to search
   * @param pool The thread pool
   * @return The final best board state that it can find.
   */
  private Board solve_pndfs(Board b, ExecutorService pool) {
    Board input = b;

    fbest_score = -1;
    fbest = null;
    currentfactors = factors;

    while (b != null && !b.finished()) {
      b = solve_pdfs(b, pool);
      if (b != null) {
        // log_info(b);
      }
    }

    // Super edge-case: The input board can't be moved...
    return fbest == null ? input : fbest;
  }
示例#4
0
  /**
   * Solves a board game using a depth-limited depth first search. Also makes use of some
   * backtracking to further optimise the result. Will also attempt to run multithreadedly.
   *
   * @param s The tile sequence
   * @param b The board to search
   * @return The final best board state that it can find.
   */
  private Board solve_mdfs(Board b) {
    Ringbuffer<Board> rb = new Ringbuffer<>(6);
    Board current = b, choke_best = null;
    char fc = 0, foff = 0;
    // VTEC just kicked in yo
    ExecutorService pool = Executors.newFixedThreadPool(nThreads);

    fbest_score = -1;
    fbest = null;
    while (current != null && !current.finished()) {
      rb.push(current);
      current = solve_pdfs(current, pool);

      if (choke_best != null && choke_best != fbest) {
        log_info(
            "Recovery!: [%d:%s] %d(%d) --> %d(%d)",
            (int) fc,
            Arrays.toString(currentfactors),
            choke_best.score(),
            choke_best.nMoves(),
            fbest.score(),
            fbest.nMoves());
        choke_best = null;
        // Test: Is it always best to stick to 18,2,2,9 where possible?
        // Maybe not, but some factors shouldn't be used for extended periods of time.
        if (fc > 3) {
          log_info(
              "Volatile weights were used; switching back to %s",
              Arrays.toString(choicefactors[0]));
          fc = 0;
          currentfactors = choicefactors[0];
        }
      }

      if (current != null) {
        log_info(current);
      } else if (fbest != null && fbest.nMoves() < tileSequence.length) {
        current = rb.pop();

        if (choke_best != fbest) {
          choke_best = fbest;
          foff = 1;
          fc = (char) ((fc + 1) % choicefactors.length);
          currentfactors = choicefactors[fc];
          log_info("Dead-end, back-tracking two steps and trying with different weights!");
          log_info(
              "Starting index: %d (current score %d/%d)",
              (int) fc, current.score(), current.nMoves());
        } else if (foff++ < choicefactors.length - 1) {
          fc = (char) ((fc + 1) % choicefactors.length);
          currentfactors = choicefactors[fc];
          log_info("No improvement, trying factor index %d...", (int) fc);
        } else {
          current = null;
          log_info("Factor exhaustion");
        }
      }
    }

    pool.shutdown();
    return fbest == null ? b : fbest;
  }