Class DoubleArrayIndirectPriorityQueue

java.lang.Object
it.unimi.dsi.fastutil.doubles.DoubleArrayIndirectPriorityQueue
All Implemented Interfaces:
DoubleIndirectPriorityQueue, IndirectPriorityQueue<Double>

public class DoubleArrayIndirectPriorityQueue extends Object implements DoubleIndirectPriorityQueue
A type-specific array-based semi-indirect priority queue.

Instances of this class use as reference list a reference array, which must be provided to each constructor, and represent a priority queue using a backing array of integer indices—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.

Implementation Specification:
This implementation is extremely inefficient, but it is difficult to beat when the size of the queue is very small. Moreover, it allows to enqueue several time the same index, without limitations.
  • Constructor Details

    • DoubleArrayIndirectPriorityQueue

      public DoubleArrayIndirectPriorityQueue(double[] refArray, int capacity, DoubleComparator c)
      Creates a new empty queue without elements 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.
    • DoubleArrayIndirectPriorityQueue

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

      public DoubleArrayIndirectPriorityQueue(double[] refArray, DoubleComparator 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.
    • DoubleArrayIndirectPriorityQueue

      public DoubleArrayIndirectPriorityQueue(double[] 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.
    • DoubleArrayIndirectPriorityQueue

      public DoubleArrayIndirectPriorityQueue(double[] refArray, int[] a, int size, DoubleComparator 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:
      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.
    • DoubleArrayIndirectPriorityQueue

      public DoubleArrayIndirectPriorityQueue(double[] refArray, int[] a, DoubleComparator 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:
      refArray - the reference array.
      a - an array of indices into refArray.
      c - the comparator used in this queue, or null for the natural order.
    • DoubleArrayIndirectPriorityQueue

      public DoubleArrayIndirectPriorityQueue(double[] 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.

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

      public DoubleArrayIndirectPriorityQueue(double[] 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.

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