Class PriorityQueue<T>

    • Constructor Summary

      Constructors 
      Constructor Description
      PriorityQueue​(int maxSize)  
      PriorityQueue​(int maxSize, boolean prepopulate)  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      T add​(T element)
      Adds an Object to a PriorityQueue in log(size) time.
      void clear()
      Removes all entries from the PriorityQueue.
      T insertWithOverflow​(T element)
      Adds an Object to a PriorityQueue in log(size) time.
      T pop()
      Removes and returns the least element of the PriorityQueue in log(size) time.
      int size()
      Returns the number of elements currently stored in the PriorityQueue.
      T top()
      Returns the least element of the PriorityQueue in constant time.
      T updateTop()
      Should be called when the Object at top changes values.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • PriorityQueue

        public PriorityQueue​(int maxSize)
      • PriorityQueue

        public PriorityQueue​(int maxSize,
                             boolean prepopulate)
    • Method Detail

      • add

        public final T add​(T element)
        Adds an Object to a PriorityQueue in log(size) time. If one tries to add more objects than maxSize from initialize an ArrayIndexOutOfBoundsException is thrown.
        Returns:
        the new 'top' element in the queue.
      • insertWithOverflow

        public T insertWithOverflow​(T element)
        Adds an Object to a PriorityQueue in log(size) time. It returns the object (if any) that was dropped off the heap because it was full. This can be the given parameter (in case it is smaller than the full heap's minimum, and couldn't be added), or another object that was previously the smallest value in the heap and now has been replaced by a larger one, or null if the queue wasn't yet full with maxSize elements.
      • top

        public final T top()
        Returns the least element of the PriorityQueue in constant time.
      • pop

        public final T pop()
        Removes and returns the least element of the PriorityQueue in log(size) time.
      • updateTop

        public final T updateTop()
        Should be called when the Object at top changes values. Still log(n) worst case, but it's at least twice as fast to
         pq.top().change();
         pq.updateTop();
         
        instead of
         o = pq.pop();
         o.change();
         pq.push(o);
         
        Returns:
        the new 'top' element.
      • size

        public final int size()
        Returns the number of elements currently stored in the PriorityQueue.
      • clear

        public final void clear()
        Removes all entries from the PriorityQueue.