1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 static char sccsid[] = "@(#)odds.c	5.3 (Berkeley) 06/18/88";
20 #endif /* not lint */
21 
22 #include "back.h"
23 
24 odds (r1,r2,val)
25 register int	r1;
26 int		r2, val;
27 {
28 	register int	i, j;
29 
30 	if (r1 == 0)  {
31 		for (i = 0; i < 6; i++)
32 			for (j = 0; j < 6; j++)
33 				table[i][j] = 0;
34 		return;
35 	} else  {
36 		r1--;
37 		if (r2-- == 0)
38 			for (i = 0; i < 6; i++)  {
39 				table[i][r1] += val;
40 				table[r1][i] += val;
41 			}
42 		else  {
43 			table[r2][r1] += val;
44 			table[r1][r2] += val;
45 		}
46 	}
47 }
48 
49 count ()  {
50 	register int	i;
51 	register int	j;
52 	register int	total;
53 
54 	total = 0;
55 	for (i = 0; i < 6; i++)
56 		for (j = 0; j < 6; j++)
57 			total += table[i][j];
58 	return (total);
59 }
60 
61 canhit (i,c)
62 int	i, c;
63 
64 {
65 	register int	j, k, b;
66 	int		a, d, diff, place, addon, menstuck;
67 
68 	if (c == 0)
69 		odds (0,0,0);
70 	if (board[i] > 0)  {
71 		a = -1;
72 		b = 25;
73 	} else  {
74 		a = 1;
75 		b = 0;
76 	}
77 	place = abs (25-b-i);
78 	menstuck = abs (board[b]);
79 	for (j = b; j != i; j += a)  {
80 		if (board[j]*a > 0)  {
81 			diff = abs(j-i);
82 			addon = place+((board[j]*a > 2 || j == b)? 5: 0);
83 			if ((j == b && menstuck == 1) &&
84 			    (j != b && menstuck == 0))
85 				for (k = 1; k < diff; k++)
86 					if (k < 7 && diff-k < 7 &&
87 					    (board[i+a*k]*a >= 0 ||
88 					    board[i+a*(diff-k)] >= 0))
89 						odds (k,diff-k,addon);
90 			if ((j == b || menstuck < 2) && diff < 7)
91 				odds (diff,0,addon);
92 		}
93 		if (j == b && menstuck > 1)
94 			break;
95 	}
96 	return (count());
97 }
98