Package it.unimi.dsi.fastutil.ints

Class IntHeapIndirectPriorityQueue

java.lang.Object
it.unimi.dsi.fastutil.ints.IntHeapSemiIndirectPriorityQueue
it.unimi.dsi.fastutil.ints.IntHeapIndirectPriorityQueue
All Implemented Interfaces:
IndirectPriorityQueue<java.lang.Integer>, IntIndirectPriorityQueue
public class IntHeapIndirectPriorityQueue
extends IntHeapSemiIndirectPriorityQueue
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 IntHeapSemiIndirectPriorityQueue.trim() method to reduce its size, if necessary.

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

  • Constructor Summary

    Constructors
    Constructor Description
    IntHeapIndirectPriorityQueue​(int[] refArray)
    Creates a new empty queue with capacity equal to the length of the reference array and using the natural order.
    IntHeapIndirectPriorityQueue​(int[] refArray, int capacity)
    Creates a new empty queue with a given capacity and using the natural order.
    IntHeapIndirectPriorityQueue​(int[] refArray, int[] a)
    Wraps a given array in a queue using the natural order.
    IntHeapIndirectPriorityQueue​(int[] refArray, int[] a, int size)
    Wraps a given array in a queue using the natural order.
    IntHeapIndirectPriorityQueue​(int[] refArray, int[] a, int size, IntComparator c)
    Wraps a given array in a queue using a given comparator.
    IntHeapIndirectPriorityQueue​(int[] refArray, int[] a, IntComparator c)
    Wraps a given array in a queue using a given comparator.
    IntHeapIndirectPriorityQueue​(int[] refArray, int capacity, IntComparator c)
    Creates a new empty queue with a given capacity and comparator.
    IntHeapIndirectPriorityQueue​(int[] refArray, IntComparator c)
    Creates a new empty queue with capacity equal to the length of the reference array and a given comparator.

  • Method Summary

    Modifier and Type Method Description
    void allChanged()
    Rebuilds this queue in a bottom-up fashion (in linear time).
    void changed()
    Notifies this queue that the first element has changed (optional operation).
    void changed​(int index)
    Notifies this queue that the specified element has changed (optional operation).
    void clear()
    Removes all elements from this queue.
    boolean contains​(int index)
    Checks whether a given index belongs to this queue (optional operation).
    int dequeue()
    Dequeues the first element from this queue.
    void enqueue​(int x)
    Enqueues a new element.
    boolean remove​(int index)
    Removes the specified element from this queue (optional operation).

    Methods inherited from class it.unimi.dsi.fastutil.ints.IntHeapSemiIndirectPriorityQueue

    comparator, first, front, size, toString, trim

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

    Methods inherited from interface it.unimi.dsi.fastutil.IndirectPriorityQueue

    isEmpty, last

  • Constructor Details

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] refArray, int capacity, IntComparator 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] refArray, IntComparator 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] refArray, int[] a, int size, IntComparator 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] refArray, int[] a, IntComparator 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] 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.

    • IntHeapIndirectPriorityQueue

      public IntHeapIndirectPriorityQueue​(int[] 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