view make/test/Queens.java @ 889:15c5903cf9e1

6865703: G1: Parallelize hot card cache cleanup Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads. Reviewed-by: jmasa, tonyp
author johnc
date Mon, 03 Aug 2009 12:59:30 -0700
parents d1605aabd0a1
children c18cbe5936b8
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/*
 * Copyright 2006-2008 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

import java.util.*;

// Copyright 1996, Animorphic Systems
// gri 28 Aug 92 / 15 Jan 93 / 8 Dec 95

class Queens {

  static void try_i(boolean a[], boolean b[], boolean c[], int x[], int i) {
    int adj = 7;

    for (int j = 1; j <= 8; j++) {
      if (b[j] && a[i+j] && c[adj+i-j]) {
        x[i] = j;
        b[j] = false;
        a[i+j] = false;
        c[adj+i-j] = false;
        if (i < 8) try_i(a, b, c, x, i+1);
        else print(x);
        b[j] = true;
        a[i+j] = true;
        c[adj+i-j] = true;
      }
    }
  }

  public static void main(String s[]) {
    boolean a[] = new boolean[16+1];
    boolean b[] = new boolean[ 8+1];
    boolean c[] = new boolean[14+1];
    int     x[] = new int[8+1];
    int adj = 7;

    for (int i = -7; i <= 16; i++) {
      if (i >= 1 && i <= 8) b[i]     = true;
      if (i >= 2)           a[i]     = true;
      if (i <= 7)           c[adj+i] = true;
    }

    x[0] = 0; // solution counter

    try_i(a, b, c, x, 1);
  }

  static void print(int x[]) {
    // first correct solution: A1 B5 C8 D6 E3 F7 G2 H4

    char LF = (char)0xA;
    char CR = (char)0xD;

    x[0]++;
    if (x[0] < 10)
        System.out.print(" ");
    System.out.print(x[0] + ". ");
    for (int i = 1; i <= 8; i++) {
      char p = (char)('A' + i - 1);
      System.out.print(p);
      System.out.print (x[i] + " ");
    }
    System.out.println();
  }

};