1 /* $NetBSD: odds.c,v 1.7 2006/03/22 04:22:05 christos Exp $ */
2
3 /*
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)odds.c 8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: odds.c,v 1.7 2006/03/22 04:22:05 christos Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include "back.h"
42
43 void
odds(int r1,int r2,int val)44 odds(int r1, int r2, int val)
45 {
46 int i, j;
47
48 if (r1 == 0) {
49 for (i = 0; i < 6; i++)
50 for (j = 0; j < 6; j++)
51 table[i][j] = 0;
52 return;
53 } else {
54 r1--;
55 if (r2-- == 0) {
56 for (i = 0; i < 6; i++) {
57 table[i][r1] += val;
58 table[r1][i] += val;
59 }
60 } else {
61 table[r2][r1] += val;
62 table[r1][r2] += val;
63 }
64 }
65 }
66
67 int
count(void)68 count(void)
69 {
70 int i;
71 int j;
72 int total;
73
74 total = 0;
75 for (i = 0; i < 6; i++)
76 for (j = 0; j < 6; j++)
77 total += table[i][j];
78 return (total);
79 }
80
81 int
canhit(int i,int c)82 canhit(int i, int c)
83 {
84 int j, k, b;
85 int a, diff, place, addon, menstuck;
86
87 if (c == 0)
88 odds(0, 0, 0);
89 if (board[i] > 0) {
90 a = -1;
91 b = 25;
92 } else {
93 a = 1;
94 b = 0;
95 }
96 place = abs(25 - b - i);
97 menstuck = abs(board[b]);
98 for (j = b; j != i; j += a) {
99 if (board[j] * a > 0) {
100 diff = abs(j - i);
101 addon = place + ((board[j] * a > 2 || j == b) ? 5 : 0);
102 if ((j == b && menstuck == 1) ||
103 (j != b && menstuck == 0))
104 for (k = 1; k < diff; k++)
105 if (k < 7 && diff - k < 7 &&
106 (board[i + a * k] * a >= 0 ||
107 board[i + a * (diff - k)] >= 0))
108 odds(k, diff - k, addon);
109 if ((j == b || menstuck < 2) && diff < 7)
110 odds(diff, 0, addon);
111 }
112 if (j == b && menstuck > 1)
113 break;
114 }
115 return (count());
116 }
117