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Interface jdsl.simple.api.SimplePriorityQueue

public interface SimplePriorityQueue

extends Container

A priority queue defines a total order relation, usually induced by a comparator. A priority queue stores a collection of items (each of which is a key-element pair); it supports the insertion of items whose key in the domain of the total order relation, and the access and removal of items with smallest key.

This interface in the "simple" package defines only the basic methods of a priority queue.

See Also:

EmptyContainerException, InvalidKeyException, Comparator, PriorityQueue

insertItem(Object, Object)

Insert an item (key-element pair).

minElement()

Inspect an element (not a key) with smallest key, without modifying the priority queue.

minKey()

Inspect a smallest key (not its element), without modifying the priority queue.

removeMinElement()

Remove an item (key,element) with smallest key.

 public abstract Object minElement() throws EmptyContainerException

Inspect an element (not a key) with smallest key, without modifying the priority queue.

Returns:

element with smallest key.

Throws: EmptyContainerException

if the container is empty.

 public abstract Object minKey() throws EmptyContainerException

Inspect a smallest key (not its element), without modifying the priority queue.

Returns:

a smallest key.

Throws: EmptyContainerException

if the container is empty.

 public abstract void insertItem(Object key,
                                 Object element) throws InvalidKeyException

Insert an item (key-element pair).

Parameters:

key - object.

element - arbitrary object.

Throws: InvalidKeyException

is thrown if the key is not in the domain of the total order relation.

 public abstract Object removeMinElement() throws EmptyContainerException

Remove an item (key,element) with smallest key.

Returns:

element (not the key) of the removed item.

Throws: InvalidKeyException

is thrown if the key is not in the domain of the total order relation.

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