brazilqert.blogg.se - Enqueue dequeue java example

#Enqueue dequeue java example full#

front() will print front element of queue if queue is not.* display() will print all the elements of queue * dequeue() will print underflow if queue is empty otherwise it will print deleted value.

#Enqueue dequeue java example full#

enqueue() will print overflow if queue is already full otherwise it simply insert value.

You need to perform all input operations of the queue with the help of an array. The capacity of the queue is provided and queries are given as input to perform operations on the queue Task Now for enqueue operation we increment REAR and insert an element at REAR arr=item.įor the dequeue operation, we delete an element at the FRONT index and increment FRONT by 1. In the above example of implementation of queue using array problem, first of all we are creating an array named arr of size n which means the capacity of the queue is n and initializing FRONT and REAR as -1. Refer below image to show the dequeue operation Refer below image to show the enqueue operation Refer to the below image to show an empty array creation of size 5 Let us understand implementation of queue using array problem by an example

Else we will print all elements from FRONT to REAR.

If empty we display that the queue is empty we simply return from the function and not execute further inside the function.

Firstly check whether the queue is not empty.

It will traverse the queue and print all the elements of the queue.

Otherwise, we will return the FRONT index value.

If the queue is empty then we display that the queue is empty we simply return from the function and not execute further inside the function.

First of all we need to check that queue is not empty.

If REAR=FRONT then we set -1 to both FRONT AND REAR.

If front = - 1 or front > rear then no element is available to delete.

But if REAR rear to check whether there is at least one element available for the deletion or not.

If n-1=REAR then this means the queue is already full.

Insert an element from the rear end into the queue.Įlement is inserted into the queue after checking the overflow condition n-1=REAR to check whether the queue is full or not. The REAR value represents the index up to which value is stored in the queue and the FRONT value represents the index of the first element to be dequeued Enqueue And initialize two variables FRONT and REAR with -1which means currently queue is empty. Implementation of queue using array starts with the creation of an array of size n. The addition of an element happens at an end known as REAR and deletion happens at the FRONT end. In queue insertion and deletion of elements takes place at two different ends.

The queue is the linear data structure that works on the principle of FIFO( First In First Out). An interface cannot be instantiated because it only describes what methods a class offers but does not contain implementations of those methods.Write a program that implements the operations of queue using an array Implementation of Queue using Array Operations The following table shows the six methods again grouped by operation and type of error handling: However, if the queue is empty, this method returns null, just like poll(). Like element(), peek() also returns the head element without removing it from the queue. If the queue is empty, a NoSuchElementException is thrown. The element() method returns the element from the head of the queue without removing it from the queue. Methods for viewing the queue's head element Queue.element()