PacMan/src/gr/auth/ee/dsproject/node/Queue2D.java

package gr.auth.ee.dsproject.node;

/**
 * @brief
 *    A queue implementation for (x, y) coordinates
 */
public class Queue2D
{
   int [][] q;
   //int f;
   int r;
   int size, nItem;

   public Queue2D () {
      //f = 0;
      r = 0;
      size = nItem = 0;
      q = null;
   }

   public Queue2D (int size) {
      //f = 0;
      r = -1;
      nItem = 0;
      this.size = size;
      q = new int[size][2];
   }
   
   public int size ()         { return nItem; }
   public boolean isEmpty ()  { return (nItem == 0) ? true : false; }
   public boolean isFull ()   { return (nItem >= size) ? true : false; }

   public int [] peek () {
      int [] none = {-1, -1};
      if (!isEmpty ()) {
         return q[0];   //return q[f];
      }
      else
         return none;
   }
   
   public int [] insert (int [] it) {
      int [] none = {-1, -1};
      
      if (!isFull ()) {
         ++r;
         q[r][0] = it[0];
         q[r][1] = it[1];
         ++nItem;
         return it;
      }
      else
         return none;
   }
   
   public int [] remove () {
      int [] ret = {-1, -1};
      if (!isEmpty ()) {
         ret[0] = q[0][0]; //ret[0] = q[f][0];
         ret[1] = q[0][1]; //ret[1] = q[f][1];
         for (int i=0 ; i<r ; ++i) {
            q[i][0] = q[i+1][0];
            q[i][1] = q[i+1][1];
         }
         //++f;
         --r;
         --nItem;
         return ret;
      }
      else
         return ret;
   }
}