diff options
Diffstat (limited to 'backgammon/backgammon/extra.c')
| -rw-r--r-- | backgammon/backgammon/extra.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/backgammon/backgammon/extra.c b/backgammon/backgammon/extra.c new file mode 100644 index 00000000..36ca1dd5 --- /dev/null +++ b/backgammon/backgammon/extra.c @@ -0,0 +1,253 @@ +/* + * Copyright (c) 1980 Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +static char sccsid[] = "@(#)extra.c 5.4 (Berkeley) 6/1/90"; +#endif /* not lint */ + +#include "back.h" + +#ifdef DEBUG +#include <stdio.h> +FILE *trace; +#endif + +/* + * dble() + * Have the current player double and ask opponent to accept. + */ + +dble () { + register int resp; /* response to y/n */ + + for (;;) { + writel (" doubles."); /* indicate double */ + + if (cturn == -pnum) { /* see if computer accepts */ + if (dblgood()) { /* guess not */ + writel (" Declined.\n"); + nexturn(); + cturn *= -2; /* indicate loss */ + return; + } else { /* computer accepts */ + writel (" Accepted.\n"); + gvalue *= 2; /* double game value */ + dlast = cturn; + if (tflag) + gwrite(); + return; + } + } + + /* ask if player accepts */ + writel (" Does "); + writel (cturn == 1? color[2]: color[3]); + writel (" accept?"); + + /* get response from yorn, + * a "2" means he said "p" + * for print board. */ + if ((resp = yorn ('R')) == 2) { + writel (" Reprint.\n"); + buflush(); + wrboard(); + writel (*Colorptr); + continue; + } + + /* check response */ + if (resp) { + /* accepted */ + gvalue *= 2; + dlast = cturn; + if (tflag) + gwrite(); + return; + } + + nexturn (); /* declined */ + cturn *= -2; + return; + } +} + +/* + * dblgood () + * Returns 1 if the computer would double in this position. This + * is not an exact science. The computer will decline a double that he + * would have made. Accumulated judgments are kept in the variable n, + * which is in "pips", i.e., the position of each man summed over all + * men, with opponent's totals negative. Thus, n should have a positive + * value of 7 for each move ahead, or a negative value of 7 for each one + * behind. + */ + +dblgood () { + register int n; /* accumulated judgment */ + register int OFFC = *offptr; /* no. of computer's men off */ + register int OFFO = *offopp; /* no. of player's men off */ + +#ifdef DEBUG + register int i; + if (trace == NULL) + trace = fopen ("bgtrace","w"); +#endif + + /* get real pip value */ + n = eval()*cturn; +#ifdef DEBUG + fputs ("\nDoubles:\nBoard: ",trace); + for (i = 0; i < 26; i++) + fprintf (trace," %d",board[i]); + fprintf (trace,"\n\tpip = %d, ",n); +#endif + + /* below adjusts pip value + * according to position + * judgments */ + + /* check men moving off + * board */ + if (OFFC > -15 || OFFO > -15) { + if (OFFC < 0 && OFFO < 0) { + OFFC += 15; + OFFO += 15; + n +=((OFFC-OFFO)*7)/2; + } else if (OFFC < 0) { + OFFC += 15; + n -= OFFO*7/2; + } else if (OFFO < 0) { + OFFO += 15; + n += OFFC*7/2; + } + if (OFFC < 8 && OFFO > 8) + n -= 7; + if (OFFC < 10 && OFFO > 10) + n -= 7; + if (OFFC < 12 && OFFO > 12) + n -= 7; + if (OFFO < 8 && OFFC > 8) + n += 7; + if (OFFO < 10 && OFFC > 10) + n += 7; + if (OFFO < 12 && OFFC > 12) + n += 7; + n += ((OFFC-OFFO)*7)/2; + } + +#ifdef DEBUG + fprintf (trace,"off = %d, ",n); +#endif + + /* see if men are trapped */ + n -= freemen(bar); + n += freemen(home); + n += trapped(home,-cturn); + n -= trapped(bar,cturn); + +#ifdef DEBUG + fprintf (trace,"free = %d\n",n); + fprintf (trace,"\tOFFC = %d, OFFO = %d\n",OFFC,OFFO); + fflush (trace); +#endif + + /* double if 2-3 moves ahead */ + if (n > 10+rnum(7)) + return(1); + return (0); +} + +freemen (b) +int b; + +{ + register int i, inc, lim; + + odds(0,0,0); + if (board[b] == 0) + return (0); + inc = (b == 0? 1: -1); + lim = (b == 0? 7: 18); + for (i = b+inc; i != lim; i += inc) + if (board[i]*inc < -1) + odds(abs(b-i),0,abs(board[b])); + if (abs(board[b]) == 1) + return ((36-count())/5); + return (count()/5); +} + +trapped (n,inc) +int n, inc; + +{ + register int i, j, k; + int c, l, ct; + + ct = 0; + l = n+7*inc; + for (i = n+inc; i != l; i += inc) { + odds (0,0,0); + c = abs(i-l); + if (board[i]*inc > 0) { + for (j = c; j < 13; j++) + if (board[i+inc*j]*inc < -1) { + if (j < 7) + odds (j,0,1); + for (k = 1; k < 7 && k < j; k++) + if (j-k < 7) + odds (k,j-k,1); + } + ct += abs(board[i])*(36-count()); + } + } + return (ct/5); +} + +eval () { + + register int i, j; + + for (j = i = 0; i < 26; i++) + j += (board[i] >= 0 ? i*board[i] : (25-i)*board[i]); + + if (off[1] >= 0) + j += 25*off[1]; + else + j += 25*(off[1]+15); + + if (off[0] >= 0) + j -= 25*off[0]; + else + j -= 25*(off[0]+15); + return (j); +} |