view make/test/Queens.java @ 4837:eff609af17d7

7127706: G1: re-enable survivors during the initial-mark pause Summary: Re-enable survivors during the initial-mark pause. Afterwards, the concurrent marking threads have to scan them and mark everything reachable from them. The next GC will have to wait for the survivors to be scanned. Reviewed-by: brutisso, johnc
author tonyp
date Wed, 25 Jan 2012 12:58:23 -0500
parents c18cbe5936b8
children
line wrap: on
line source

/*
 * Copyright (c) 2006, 2008, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.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();
  }

};