/*
                GNU GO - the game of Go (Wei-Chi)
                Version 1.1   last revised 3-1-89
           Copyright (C) Free Software Foundation, Inc.
                      written by Man L. Li
                      modified by Wayne Iba
                    documented by Bob Webber
*/
/*
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation - version 1.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License in file COPYING for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Please report any bug/fix, modification, suggestion to

mail address:   Man L. Li
                Dept. of Computer Science
                University of Houston
                4800 Calhoun Road
                Houston, TX 77004

e-mail address: manli@cs.uh.edu         (Internet)
                coscgbn@uhvax1.bitnet   (BITNET)
                70070,404               (CompuServe)
*/

#include <stdio.h>

#define EMPTY 0

extern unsigned char p[19][19];
extern int mymove, umove;
extern int opn[9];

extern int opening(int *i, int *j, int *cnd, int type);
extern int openregion(int i1, int j1, int i2, int j2);
extern int matchpat(int m, int n, int *i, int *j, int *val);

int findpatn(int *i, int *j, int *val)
/* find pattern to match for next move */
{
 int m, n;
 int ti, tj, tval;
 static int cnd, mtype;  /* game tree node number, move type */
/* mtype = 0, basic; 1, inverted; 2, reflected; 3, inverted & reflected */

/* open game then occupy corners */
 if (opn[4])   /* continue last move */
   {
    opn[4] = 0;  /* clear flag */
    if (opening(i, j, &cnd, mtype)) opn[4] = 1; /* more move then reset flag */
    if (p[*i][*j] == EMPTY)  /* valid move */
      {
       *val = 80;
       return 1;
     }
    else
      opn[4] = 0;
  }

 if (opn[0])   /* Northwest corner */
   {
    opn[0] = 0;  /* clear flag */
    if (openregion(0, 0, 5, 5))
      {
       cnd = 0;
       mtype = 0;
       opening(i, j, &cnd, mtype);  /* get new node for next move */
       if (opening(i, j, &cnd, mtype)) opn[4] = 1;
       *val = 80;
       return 1;
     }
 }

 if (opn[1])   /* Southwest corner */
   {
    opn[1] = 0;
    if (openregion(13, 0, 18, 5))
      {
       cnd = 0;
       mtype = 1;
       opening(i, j, &cnd, mtype);  /* get new node for next move */
       if (opening(i, j, &cnd, mtype)) opn[4] = 1;
       *val = 80;
       return 1;
     }
  }

 if (opn[2])   /* Northeast corner */
   {
    opn[2] = 0;
    if (openregion(0, 13, 5, 18))
      {
       cnd = 0;
       mtype = 2;
       opening(i, j, &cnd, mtype);  /* get new node for next move */
       if (opening(i, j, &cnd, mtype)) opn[4] = 1;
       *val = 80;
       return 1;
     }
  }

 if (opn[3])   /* Northeast corner */
   {
    opn[3] = 0;
    if (openregion(13, 13, 18, 18))
      {
       cnd = 0;
       mtype = 3;
       opening(i, j, &cnd, mtype);  /* get new node for next move */
       if (opening(i, j, &cnd, mtype)) opn[4] = 1;
       *val = 80;
       return 1;
     }
  }

/* occupy edges */
 if (opn[5])   /* North edge */
   {
    opn[5] = 0;
    if (openregion(0, 6, 4, 11))
      {
       *i = 3;
       *j = 9;
       *val = 80;
       return 1;
     }
  }

 if (opn[6])   /* South edge */
   {
    opn[6] = 0;
    if (openregion(18, 6, 14, 11))
      {
       *i = 15;
       *j = 9;
       *val = 80;
       return 1;
     }
  }

 if (opn[7])   /* West edge */
   {
    opn[7] = 0;
    if (openregion(6, 0, 11, 4))
      {
       *i = 9;
       *j = 3;
       *val = 80;
       return 1;
     }
  }

 if (opn[8])   /* East edge */
   {
    opn[8] = 0;
    if (openregion(6, 18, 11, 14))
      {
       *i = 9;
       *j = 15;
       *val = 80;
       return 1;
     }
  }

 *i = -1;
 *j = -1;
 *val = -1;

/* find local pattern */
 for (m = 0; m < 19; m++)
   for (n = 0; n < 19; n++)
     if ((p[m][n] == mymove) &&
         (matchpat(m, n, &ti, &tj, &tval) && (tval > *val)))
       {
        *val = tval;
        *i = ti;
        *j = tj;
      }
 if (*val > 0)  /* pattern found */
    return 1;
 else  /* no match found */
    return 0;
}  /* end findpatn */