Please answer these Java questions with as much detail as possible. Thank you Q.
ID: 3914598 • Letter: P
Question
Please answer these Java questions with as much detail as possible. Thank youQ.4: Explain why the implementation of a queue using a linked list requires insertion and extraction operations to be performed in different ends of the list. O_5: Explain why, to implement a queue using a linked list, it is recommended to keep a reference to the last node (tail) of the list. Q 6: Explain why, to implement a queue using a linked list, it is recommended to extract nodes from the top of the list and insert nodes a the tail of the list.
Explanation / Answer
4). A queue is a kind of data structure in which insertion is done at one end and deletion is done at the other end. So, to resemble this data structure obviously, a queue using linked list requires insertion at one end (either at the head or tail), and deletion at The other end.
Queue implementation is done by using linked list. Since in the queue nothing but the first reached must be served first so let us assume head part and tail part. The element is inserted through tail and the element in the front end is served first.
5). As discussed in the previous question, if insertion is done at one end, and deletion is done at the other end. Having two different pointers, head and tail of the linked list will make the operations of the queue (insertion, and deletion), with complexity O(1). Where as if we have only one pointer head, and not the tail, now in this case, one operation will have a complexity of O(1), and the other will have a complexity of O(n).
Last node tail must be referenced since we know that the tail element is used for queuing the next element and so that keep traking of the tail is necessary.
6). A general thinking will give a perfect reasoning for this. A queue which could be formed at any place, will people/things will be added at the last, and will be picked out of the queue from the front. And therefore, the queue follows a first-in-first-out order. Now, having extraction at the top, and insertion at the tail will ease the process of printing (if required) all the elements of the queue, in proper order, from head to tail. Where as, if it is done in the other order, now to print the elements it should be done in reverse order, i.e., last element first, then the penultimate, and so on. Which will make the print operation more complex, especially when you use a singly linked list.
To implement queue the insertion must be done tail of the node while the front element is dequeued since first element is the queue must be served first which is the concept of the Queue