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As of Java 6, Java's Collections Framework provides a new Deque interface that provides the functionality of insertion and removal at both ends. It is implemented by classes such as ArrayDeque (also new in Java 6) and LinkedList , providing the dynamic array and linked list implementations, respectively.
Behavior when the collection is empty varies – most often this yields an underflow error, identically to a pop on an empty collection, but some implementations provide a function which instead simply returns (without error), essentially implementing if isempty then return, else peek. This behavior can be axiomatized in various ways.
This is still the conceptually simplest way to construct a queue in a high-level language, but it does admittedly slow things down a little, because the array indices must be compared to zero and the array size, which is comparable to the time taken to check whether an array index is out of bounds, which some languages do, but this will ...
If the array contains all non-negative numbers, then the problem is trivial; a maximum subarray is the entire array. If the array contains all non-positive numbers, then a solution is any subarray of size 1 containing the maximal value of the array (or the empty subarray, if it is permitted).
Should a maximum size be adopted for a queue, then a circular buffer is a completely ideal implementation; all queue operations are constant time. However, expanding a circular buffer requires shifting memory, which is comparatively costly. For arbitrarily expanding queues, a linked list approach may be preferred instead.
In the case of arrays, access is done with the array index. In the case of stacks, access is done according to the LIFO (last in, first out) order and in the case of queues it is done according to the FIFO (first in, first out) order; storage, that is the way of storing the objects of the container;
is_empty: check whether the queue has no elements. insert_with_priority: add an element to the queue with an associated priority. pull_highest_priority_element: remove the element from the queue that has the highest priority, and return it. This is also known as "pop_element(Off)", "get_maximum_element" or "get_front(most)_element".
In computer science, the word dequeue can be used as: A verb meaning "to remove from a queue" An abbreviation for double-ended queue (more commonly, deque