Home | History | Annotate | Line # | Download | only in common_source 
      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
     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
     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
     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