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- /*
- * Copyright (c) 1980 Regents of the University of California.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are permitted
- * provided that this notice is preserved and that due credit is given
- * to the University of California at Berkeley. The name of the University
- * may not be used to endorse or promote products derived from this
- * software without specific prior written permission. This software
- * is provided ``as is'' without express or implied warranty.
- */
-
- #ifndef lint
- static char sccsid[] = "@(#)allow.c 5.2 (Berkeley) 2/16/88";
- #endif /* not lint */
-
- #include "back.h"
-
- movallow () {
-
- register int i, m, iold;
- int r;
-
- if (d0)
- swap;
- m = (D0 == D1? 4: 2);
- for (i = 0; i < 4; i++)
- p[i] = bar;
- i = iold = 0;
- while (i < m) {
- if (*offptr == 15)
- break;
- h[i] = 0;
- if (board[bar]) {
- if (i == 1 || m == 4)
- g[i] = bar+cturn*D1;
- else
- g[i] = bar+cturn*D0;
- if (r = makmove(i)) {
- if (d0 || m == 4)
- break;
- swap;
- movback (i);
- if (i > iold)
- iold = i;
- for (i = 0; i < 4; i++)
- p[i] = bar;
- i = 0;
- } else
- i++;
- continue;
- }
- if ((p[i] += cturn) == home) {
- if (i > iold)
- iold = i;
- if (m == 2 && i) {
- movback(i);
- p[i--] = bar;
- if (p[i] != bar)
- continue;
- else
- break;
- }
- if (d0 || m == 4)
- break;
- swap;
- movback (i);
- for (i = 0; i < 4; i++)
- p[i] = bar;
- i = 0;
- continue;
- }
- if (i == 1 || m == 4)
- g[i] = p[i]+cturn*D1;
- else
- g[i] = p[i]+cturn*D0;
- if (g[i]*cturn > home) {
- if (*offptr >= 0)
- g[i] = home;
- else
- continue;
- }
- if (board[p[i]]*cturn > 0 && (r = makmove(i)) == 0)
- i++;
- }
- movback (i);
- return (iold > i? iold: i);
- }
-