chamster.tex

数据挖掘中de一个算法 hamster的实例

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/*----------------------------------------------------------------------
  File    : control.c
  Contents: hamster control program
  Author  : Christian Borgelt
  History : 16.10.1997 file created
----------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include "hamster.h"

/*----------------------------------------------------------------------
  Functions
----------------------------------------------------------------------*/

void hms_ctrl (HAMSTER *hms)
{                               /* --- hamster control function */
  int x, y;                     /* coordinates of current field */
  int movecnt = 0;              /* number of moves made */
  int turn;                     /* turn direction (HMS_POS/HMS_NEG) */

  while (movecnt < 50) {        /* make 50 (field to field) moves */
    hms_pos(hms, &x, &y);       /* get current position in maze */
    if ((x == 0) && (y == 0))   /* if we are at home (initial pos.), */
      hms_drop(hms, HMS_MAXLOAD);    /* drop all the corn we have */
    else if (hms_corn(hms))     /* if there is corn on the field, */
      hms_take(hms, HMS_MAXLOAD);    /* take as much as we can carry */
    if ((hms_look(hms) == HMS_WALL)  /* if the way is blocked */
    ||  (RAND_MAX/4 -rand() > 0)) {  /* or just because it's funny */
      turn = (RAND_MAX/2 -rand() > 0) ? HMS_POS : HMS_NEG;
      do { hms_turn(hms, turn); /* turn hamster in random direction */
      } while (hms_look(hms) == HMS_WALL);
    }                           /* until no wall blocks the way */
    hms_move(hms); movecnt++;   /* move the hamster forward */
  }                             /* and count the move made */
}  /* hms_ctrl() */
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