#PRIORITY QUEUE IMPLEMENTATION IN JAVA CODE#

As queue is full, elements will not be inserted. A priority queue is an abstract data type, it is like a regular queue or stack data structure, but where additionally each element has a priority associated with it. Approach: The most efficient way to code our different functions is the one where add (data) and remove () takes O (log n) and peek () takes constant time. PriorityQueue queue = new PriorityQueue(6) Whenever an element is to be removed from queue, queue get the element using item count. if data is larger, shift existing item to right end Here we're assuming that data with high value has low priority. Whenever an element is inserted into queue, priority queue inserts the item according to its order. Here is my implementation of a priority queue, as a exercise from the textbook Data Structures & Other Objects Using Java. Peek − get the element at front of the queue. There is few more operations supported by queue which are following. We're going to implement Queue using array in this article.

Remove / dequeue − remove an item from the front of the queue. Insert / enqueue − add an item to the rear of the queue. A priority queue is unbounded, but has an internal capacity governing the size of an array used to store the elements on the queue. Since a priority queue needs to compare its elements and order them accordingly, the user-defined class must implement the Comparable interface, or you must. Following are the principal methods of a Priority Queue. So we're assigned priority to item based on its key value. In Priority queue items are ordered by key value so that item with the lowest value of key is at front and item with the highest value of key is at rear or vice versa. Like ordinary queue, priority queue has same method but with a major difference. Priority Queue is more specilized data structure than Queue.

Priority queue implementation in java