1 /* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 #if 0 36 static char sccsid[] = "@(#)odds.c 8.1 (Berkeley) 5/31/93"; 37 #endif 38 static const char rcsid[] = 39 "$FreeBSD: src/games/backgammon/common_source/odds.c,v 1.5 1999/11/30 03:48:26 billf Exp $"; 40 #endif /* not lint */ 41 42 #include "back.h" 43 44 odds (r1,r2,val) 45 int r1; 46 int r2, val; 47 { 48 int i, j; 49 50 if (r1 == 0) { 51 for (i = 0; i < 6; i++) 52 for (j = 0; j < 6; j++) 53 table[i][j] = 0; 54 return; 55 } else { 56 r1--; 57 if (r2-- == 0) 58 for (i = 0; i < 6; i++) { 59 table[i][r1] += val; 60 table[r1][i] += val; 61 } 62 else { 63 table[r2][r1] += val; 64 table[r1][r2] += val; 65 } 66 } 67 } 68 69 count () { 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 canhit (i,c) 82 int i, c; 83 84 { 85 int j, k, b; 86 int a, d, diff, place, addon, menstuck; 87 88 if (c == 0) 89 odds (0,0,0); 90 if (board[i] > 0) { 91 a = -1; 92 b = 25; 93 } else { 94 a = 1; 95 b = 0; 96 } 97 place = abs (25-b-i); 98 menstuck = abs (board[b]); 99 for (j = b; j != i; j += a) { 100 if (board[j]*a > 0) { 101 diff = abs(j-i); 102 addon = place+((board[j]*a > 2 || j == b)? 5: 0); 103 if ((j == b && menstuck == 1) && 104 (j != b && menstuck == 0)) 105 for (k = 1; k < diff; k++) 106 if (k < 7 && diff-k < 7 && 107 (board[i+a*k]*a >= 0 || 108 board[i+a*(diff-k)] >= 0)) 109 odds (k,diff-k,addon); 110 if ((j == b || menstuck < 2) && diff < 7) 111 odds (diff,0,addon); 112 } 113 if (j == b && menstuck > 1) 114 break; 115 } 116 return (count()); 117 } 118