mq.h

   1 #ifndef ZZGO_MQ_H
   2 #define ZZGO_MQ_H
   3
   4 /* Move queues; in fact, they are more like move lists, used to accumulate
   5  * equally good move candidates, then choosing from them randomly. */
   6
   7 #include "move.h"
   8
   9 #define MQL 64
  10 struct move_queue {
  11         int moves;
  12         coord_t move[MQL];
  13 };
  14
  15 /* Add a move to the queue. */
  16 static void mq_add(struct move_queue *q, coord_t c);
  17
  18 /* Cat two queues together. */
  19 static void mq_append(struct move_queue *qd, struct move_queue *qs);
  20
  21 /* Check if the last move in queue is not a dupe, and remove it
  22  * in that case. */
  23 static void mq_nodup(struct move_queue *q);
  24
  25
  26 static inline void
  27 mq_nodup(struct move_queue *q)
  28 {
  29         if ((q->moves > 1 && q->move[q->moves - 2] == q->move[q->moves - 1])
  30             || (q->moves > 2 && q->move[q->moves - 3] == q->move[q->moves - 1])
  31             || (q->moves > 3 && q->move[q->moves - 4] == q->move[q->moves - 1]))
  32                 q->moves--;
  33 }
  34
  35 static inline void
  36 mq_append(struct move_queue *qd, struct move_queue *qs)
  37 {
  38         assert(qd->moves + qs->moves < MQL);
  39         memcpy(&qd->move[qd->moves], qs->move, qs->moves * sizeof(*qs->move));
  40         qd->moves += qs->moves;
  41 }
  42
  43 static inline void
  44 mq_add(struct move_queue *q, coord_t c)
  45 {
  46         assert(q->moves < MQL);
  47         q->move[q->moves++] = c;
  48 }
  49
  50 #endif