Search results
Results From The WOW.Com Content Network
Queue overflow results from trying to add an element onto a full queue and queue underflow happens when trying to remove an element from an empty queue. A bounded queue is a queue limited to a fixed number of items. [1] There are several efficient implementations of FIFO queues.
When a user asks to clear the browsing history for the past hour, the most recently added entries are removed. One example where a deque can be used is the work stealing algorithm. [9] This algorithm implements task scheduling for several processors. A separate deque with threads to be executed is maintained for each processor.
For queue, because enqueuing and dequeuing occur at opposite ends, peek cannot be implemented in terms of basic operations, and thus is often implemented separately. One case in which peek is not trivial is in an ordered list type (i.e., elements accessible in order) implemented by a self-balancing binary search tree .
A priority queue must at least support the following operations: 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.
enter the monitor: enter the method if the monitor is locked add this thread to e block this thread else lock the monitor leave the monitor: schedule return from the method wait c: add this thread to c.q schedule block this thread notify c: if there is a thread waiting on c.q select and remove one thread t from c.q (t is called "the notified ...
the producer must wait for the consumer to consume something if the queue is full. The semaphore solution to the producer–consumer problem tracks the state of the queue with two semaphores: emptyCount, the number of empty places in the queue, and fullCount, the number of elements in the queue.
One example application of the double-ended priority queue is external sorting. In an external sort, there are more elements than can be held in the computer's memory. The elements to be sorted are initially on a disk and the sorted sequence is to be left on the disk. The external quick sort is implemented using the DEPQ as follows:
The bucket queue is the priority-queue analogue of pigeonhole sort (also called bucket sort), a sorting algorithm that places elements into buckets indexed by their priorities and then concatenates the buckets. Using a bucket queue as the priority queue in a selection sort gives a form of the pigeonhole sort algorithm. [2]