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 * @(#)odds.c 8.1 (Berkeley) 5/31/93 34 * $FreeBSD: src/games/backgammon/common_source/odds.c,v 1.5 1999/11/30 03:48:26 billf Exp $ 35 * $DragonFly: src/games/backgammon/common_source/odds.c,v 1.2 2003/06/17 04:25:22 dillon Exp $ 36 */ 37 38 #include "back.h" 39 40 odds (r1,r2,val) 41 int r1; 42 int r2, val; 43 { 44 int i, j; 45 46 if (r1 == 0) { 47 for (i = 0; i < 6; i++) 48 for (j = 0; j < 6; j++) 49 table[i][j] = 0; 50 return; 51 } else { 52 r1--; 53 if (r2-- == 0) 54 for (i = 0; i < 6; i++) { 55 table[i][r1] += val; 56 table[r1][i] += val; 57 } 58 else { 59 table[r2][r1] += val; 60 table[r1][r2] += val; 61 } 62 } 63 } 64 65 count () { 66 int i; 67 int j; 68 int total; 69 70 total = 0; 71 for (i = 0; i < 6; i++) 72 for (j = 0; j < 6; j++) 73 total += table[i][j]; 74 return (total); 75 } 76 77 canhit (i,c) 78 int i, c; 79 80 { 81 int j, k, b; 82 int a, d, diff, place, addon, menstuck; 83 84 if (c == 0) 85 odds (0,0,0); 86 if (board[i] > 0) { 87 a = -1; 88 b = 25; 89 } else { 90 a = 1; 91 b = 0; 92 } 93 place = abs (25-b-i); 94 menstuck = abs (board[b]); 95 for (j = b; j != i; j += a) { 96 if (board[j]*a > 0) { 97 diff = abs(j-i); 98 addon = place+((board[j]*a > 2 || j == b)? 5: 0); 99 if ((j == b && menstuck == 1) && 100 (j != b && menstuck == 0)) 101 for (k = 1; k < diff; k++) 102 if (k < 7 && diff-k < 7 && 103 (board[i+a*k]*a >= 0 || 104 board[i+a*(diff-k)] >= 0)) 105 odds (k,diff-k,addon); 106 if ((j == b || menstuck < 2) && diff < 7) 107 odds (diff,0,addon); 108 } 109 if (j == b && menstuck > 1) 110 break; 111 } 112 return (count()); 113 } 114