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comparison build/test/Queens.java @ 0:a61af66fc99e jdk7-b24

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author duke
date Sat, 01 Dec 2007 00:00:00 +0000
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-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 import java.util.*;
26
27 // Copyright 1996, Animorphic Systems
28 // gri 28 Aug 92 / 15 Jan 93 / 8 Dec 95
29
30 class Queens {
31
32 static void try_i(boolean a[], boolean b[], boolean c[], int x[], int i) {
33 int adj = 7;
34
35 for (int j = 1; j <= 8; j++) {
36 if (b[j] && a[i+j] && c[adj+i-j]) {
37 x[i] = j;
38 b[j] = false;
39 a[i+j] = false;
40 c[adj+i-j] = false;
41 if (i < 8) try_i(a, b, c, x, i+1);
42 else print(x);
43 b[j] = true;
44 a[i+j] = true;
45 c[adj+i-j] = true;
46 }
47 }
48 }
49
50 public static void main(String s[]) {
51 boolean a[] = new boolean[16+1];
52 boolean b[] = new boolean[ 8+1];
53 boolean c[] = new boolean[14+1];
54 int x[] = new int[8+1];
55 int adj = 7;
56
57 for (int i = -7; i <= 16; i++) {
58 if (i >= 1 && i <= 8) b[i] = true;
59 if (i >= 2) a[i] = true;
60 if (i <= 7) c[adj+i] = true;
61 }
62
63 x[0] = 0; // solution counter
64
65 try_i(a, b, c, x, 1);
66 }
67
68 static void print(int x[]) {
69 // first correct solution: A1 B5 C8 D6 E3 F7 G2 H4
70
71 char LF = (char)0xA;
72 char CR = (char)0xD;
73
74 x[0]++;
75 if (x[0] < 10)
76 System.out.print(" ");
77 System.out.print(x[0] + ". ");
78 for (int i = 1; i <= 8; i++) {
79 char p = (char)('A' + i - 1);
80 System.out.print(p);
81 System.out.print (x[i] + " ");
82 }
83 System.out.println();
84 }
85
86 };