Package it.unimi.dsi.fastutil.shorts

Class ShortHeapIndirectPriorityQueue

java.lang.Object
it.unimi.dsi.fastutil.shorts.ShortHeapSemiIndirectPriorityQueue
it.unimi.dsi.fastutil.shorts.ShortHeapIndirectPriorityQueue
All Implemented Interfaces:
it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>, ShortIndirectPriorityQueue
public class ShortHeapIndirectPriorityQueue
extends ShortHeapSemiIndirectPriorityQueue
A type-specific heap-based indirect priority queue.

Instances of this class use an additional inversion array, of the same length of the reference array, to keep track of the heap position containing a given element of the reference array. The priority queue is represented using a heap. The heap is enlarged as needed, but it is never shrunk. Use the ShortHeapSemiIndirectPriorityQueue.trim() method to reduce its size, if necessary.

Implementation Specification:
This implementation does not allow one to enqueue several times the same index.

  • Constructor Details

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int capacity, ShortComparator c)
      Creates a new empty queue with a given capacity and comparator.
      Parameters:
      refArray - the reference array.
      capacity - the initial capacity of this queue.
      c - the comparator used in this queue, or null for the natural order.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int capacity)
      Creates a new empty queue with a given capacity and using the natural order.
      Parameters:
      refArray - the reference array.
      capacity - the initial capacity of this queue.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, ShortComparator c)
      Creates a new empty queue with capacity equal to the length of the reference array and a given comparator.
      Parameters:
      refArray - the reference array.
      c - the comparator used in this queue, or null for the natural order.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray)
      Creates a new empty queue with capacity equal to the length of the reference array and using the natural order.
      Parameters:
      refArray - the reference array.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int[] a, int size, ShortComparator c)
      Wraps a given array in a queue using a given comparator.

      The queue returned by this method will be backed by the given array. The first size element of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).

      Parameters:
      refArray - the reference array.
      a - an array of indices into refArray.
      size - the number of elements to be included in the queue.
      c - the comparator used in this queue, or null for the natural order.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int[] a, ShortComparator c)
      Wraps a given array in a queue using a given comparator.

      The queue returned by this method will be backed by the given array. The elements of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).

      Parameters:
      refArray - the reference array.
      a - an array of indices into refArray.
      c - the comparator used in this queue, or null for the natural order.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int[] a, int size)
      Wraps a given array in a queue using the natural order.

      The queue returned by this method will be backed by the given array. The first size element of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).

      Parameters:
      refArray - the reference array.
      a - an array of indices into refArray.
      size - the number of elements to be included in the queue.

    • ShortHeapIndirectPriorityQueue

      public ShortHeapIndirectPriorityQueue​(short[] refArray, int[] a)
      Wraps a given array in a queue using the natural order.

      The queue returned by this method will be backed by the given array. The elements of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).

      Parameters:
      refArray - the reference array.
      a - an array of indices into refArray.

  • Method Details

    • enqueue

      public void enqueue​(int x)
      Specified by:
      enqueue in interface it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>
      Overrides:
      enqueue in class ShortHeapSemiIndirectPriorityQueue

    • contains

      public boolean contains​(int index)

    • dequeue

      public int dequeue()
      Specified by:
      dequeue in interface it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>
      Overrides:
      dequeue in class ShortHeapSemiIndirectPriorityQueue

    • changed

      public void changed()
      Description copied from class: ShortHeapSemiIndirectPriorityQueue

      The caller must guarantee that when this method is called the index of the first element appears just once in the queue. Failure to do so will bring the queue in an inconsistent state, and will cause unpredictable behaviour.

      Specified by:
      changed in interface it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>
      Overrides:
      changed in class ShortHeapSemiIndirectPriorityQueue

    • changed

      public void changed​(int index)

    • allChanged

      public void allChanged()
      Rebuilds this queue in a bottom-up fashion (in linear time).
      Specified by:
      allChanged in interface it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>
      Overrides:
      allChanged in class ShortHeapSemiIndirectPriorityQueue

    • remove

      public boolean remove​(int index)

    • clear

      public void clear()
      Specified by:
      clear in interface it.unimi.dsi.fastutil.IndirectPriorityQueue<java.lang.Short>
      Overrides:
      clear in class ShortHeapSemiIndirectPriorityQueue