1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/make/test/Queens.java Wed Apr 09 14:22:48 2008 -0400
1.3 @@ -0,0 +1,86 @@
1.4 +/*
1.5 + * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +import java.util.*;
1.29 +
1.30 +// Copyright 1996, Animorphic Systems
1.31 +// gri 28 Aug 92 / 15 Jan 93 / 8 Dec 95
1.32 +
1.33 +class Queens {
1.34 +
1.35 + static void try_i(boolean a[], boolean b[], boolean c[], int x[], int i) {
1.36 + int adj = 7;
1.37 +
1.38 + for (int j = 1; j <= 8; j++) {
1.39 + if (b[j] && a[i+j] && c[adj+i-j]) {
1.40 + x[i] = j;
1.41 + b[j] = false;
1.42 + a[i+j] = false;
1.43 + c[adj+i-j] = false;
1.44 + if (i < 8) try_i(a, b, c, x, i+1);
1.45 + else print(x);
1.46 + b[j] = true;
1.47 + a[i+j] = true;
1.48 + c[adj+i-j] = true;
1.49 + }
1.50 + }
1.51 + }
1.52 +
1.53 + public static void main(String s[]) {
1.54 + boolean a[] = new boolean[16+1];
1.55 + boolean b[] = new boolean[ 8+1];
1.56 + boolean c[] = new boolean[14+1];
1.57 + int x[] = new int[8+1];
1.58 + int adj = 7;
1.59 +
1.60 + for (int i = -7; i <= 16; i++) {
1.61 + if (i >= 1 && i <= 8) b[i] = true;
1.62 + if (i >= 2) a[i] = true;
1.63 + if (i <= 7) c[adj+i] = true;
1.64 + }
1.65 +
1.66 + x[0] = 0; // solution counter
1.67 +
1.68 + try_i(a, b, c, x, 1);
1.69 + }
1.70 +
1.71 + static void print(int x[]) {
1.72 + // first correct solution: A1 B5 C8 D6 E3 F7 G2 H4
1.73 +
1.74 + char LF = (char)0xA;
1.75 + char CR = (char)0xD;
1.76 +
1.77 + x[0]++;
1.78 + if (x[0] < 10)
1.79 + System.out.print(" ");
1.80 + System.out.print(x[0] + ". ");
1.81 + for (int i = 1; i <= 8; i++) {
1.82 + char p = (char)('A' + i - 1);
1.83 + System.out.print(p);
1.84 + System.out.print (x[i] + " ");
1.85 + }
1.86 + System.out.println();
1.87 + }
1.88 +
1.89 +};
