Package it.unimi.dsi.fastutil.ints

Class IntArrayPriorityQueue

java.lang.Object
it.unimi.dsi.fastutil.ints.IntArrayPriorityQueue
All Implemented Interfaces:
IntPriorityQueue, PriorityQueue<java.lang.Integer>, java.io.Serializable
public class IntArrayPriorityQueue
extends java.lang.Object
implements IntPriorityQueue, java.io.Serializable
A type-specific array-based priority queue.

Instances of this class represent a priority queue using a backing array—all operations are performed directly on the array. The array is enlarged as needed, but it is never shrunk. Use the trim() method to reduce its size, if necessary.

See Also:
Serialized Form
Implementation Specification:
This implementation is extremely inefficient, but it is difficult to beat when the size of the queue is very small.

  • Constructor Summary

    Constructors
    Constructor Description
    IntArrayPriorityQueue()
    Creates a new empty queue using the natural order.
    IntArrayPriorityQueue​(int capacity)
    Creates a new empty queue with a given capacity and using the natural order.
    IntArrayPriorityQueue​(int[] a)
    Wraps a given array in a queue using the natural order.
    IntArrayPriorityQueue​(int[] a, int size)
    Wraps a given array in a queue using the natural order.
    IntArrayPriorityQueue​(int[] a, int size, IntComparator c)
    Wraps a given array in a queue using a given comparator.
    IntArrayPriorityQueue​(int[] a, IntComparator c)
    Wraps a given array in a queue using a given comparator.
    IntArrayPriorityQueue​(int capacity, IntComparator c)
    Creates a new empty queue with a given capacity and comparator.
    IntArrayPriorityQueue​(IntComparator c)
    Creates a new empty queue with a given comparator.

  • Method Summary

    Modifier and Type Method Description
    void changed()
    Notifies the queue that the first element has changed (optional operation).
    void clear()
    Removes all elements from this queue.
    IntComparator comparator()
    Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
    int dequeueInt()
    Dequeues the first element from the queue.
    void enqueue​(int x)
    Enqueues a new element.
    int firstInt()
    Returns the first element of the queue.
    int size()
    Returns the number of elements in this queue.
    void trim()
    Trims the underlying array so that it has exactly size() elements.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface it.unimi.dsi.fastutil.ints.IntPriorityQueue

    dequeue, enqueue, first, last, lastInt

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

    isEmpty

  • Constructor Details

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(int capacity, IntComparator c)
      Creates a new empty queue with a given capacity and comparator.
      Parameters:
      capacity - the initial capacity of this queue.
      c - the comparator used in this queue, or null for the natural order.

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(int capacity)
      Creates a new empty queue with a given capacity and using the natural order.
      Parameters:
      capacity - the initial capacity of this queue.

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(IntComparator c)
      Creates a new empty queue with a given comparator.
      Parameters:
      c - the comparator used in this queue, or null for the natural order.

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue()
      Creates a new empty queue using the natural order.

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(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.

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

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(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.

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

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(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.

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

    • IntArrayPriorityQueue

      public IntArrayPriorityQueue​(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.

      Parameters:
      a - an array.

  • Method Details