Write a c program for doubly linked list

History[ edit ] Stacks entered the computer science literature inwhen Alan M.

Write a c program for doubly linked list

Harris Butt 2 months ago Why are you making a cur and per node dynamically Instead you can take two node type pointers in insert-position function… what are their purpose they remain empty after a new node is inserted between them and what happen to the nodes which are present at the place of cur and pre…??

write a c program for doubly linked list

Reply Jaimie 5 months ago This tutorial is rather sloppy. I recommend against using this tutorial. This is not wrong per se, but it does fail to illustrate what happens when inserting in the middle of the list. If this is followed by a call to createnode, the program crashes, due to the questionable choice of logic in createnode.

It leaves the tail pointer dangling potential crash if the list had exactly one element before the deletion. It leaves the head pointer dangling potential crash if the list had exactly one element before the deletion. It crashes if pos is greater than the list length.

I count nine distinct memory leaks in the seven functions presented, and that ignores the leak from the lack of a destructor. Reply Blank 5 months ago First of all the tutorials do not include error checking because they are out of scope from what its thought the concepts.

I suspect you are looking for an all in one answer in implementing a link list instead of understanding how each method works. Methods that are used to delete at the beginning are already implemented by delete first or insert first.

Instead, the methods implemented are use to delete and insert nodes at N position by traversing through the link list, which is why the loops start from 1. Your argument on the tail pointer being updated on insert start is invalid. Because there is no reason for a tail pointer to be updated if you add a node to the front, only the head pointer is needed to change because the head pointer is meant to keep track of the front of the list and tail pointer to the back of the list.

If you update the tail pointer, your program will lose track of the back of the node, which does not point at the end of the list anymore. Your delete first and delete the last argument, failing on an empty list can be easily done by having an exception thrown if a list is empty.

Exception handling is meant to be done by us programmers and not tutorials.

write a c program for doubly linked list

You are missing the point of the tutorial teaching the concepts of how link list work and not error proofing the link list, that will make the tutorial out of scope.

If you do not want to look stupid. Learn how things work before making assumption about things. What you are describing is an incomplete tutorial, which should still acknowledge where it is incomplete. Furthermore, even an incomplete tutorial should not contain such basic errors as the gratuitous memory leaks in most of the functions eight of the nine leaks I mentioned are gratuitous in that the code goes out of its way to allocate memory that is never freed.

If this is supposed to be just an introduction to how a linked list operates, maybe it should skip the code snippets completely. After all, with std:: Either teach how to code an implementation well, or be satisfied with just explaining the concepts.

As for looking stupid, I have no fear of that as long as my post is next to yours. Keep in mind that the case in question is when the list started empty. So initially, no node is the back of the list. After the insertion, the list consists of a single element, which is both the front and the back of the list.

That is, the back of the list changed, from nothing to something. Since the tail pointer is meant to keep track of the back of the list, it should also change.

Care to explain that?

Deleting the Last Node from a Circular Linked List

Comprehensive should focus on the concepts of how things work, I would rather have a tutorial that gives code snippets explaining the concepts with a basic implementation rather with a full code given. Because if you learn how to each concept work you will know how to easily handle error exception yourself and change the code yourself.

It shows that you understand the concepts why something work and not work.

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What you want is a copy paste brain-dead code, implementing a link list without knowing whats happening behind the scenes. Reply Blank 5 months ago For your second reply, as I said, repeatedly. The tutorial focus on the concepts and not error handling. Inserting to the front of the list is just a basic implementation of how a list is added to the front when a node is already created.

The obvious assumption is that there is at least 1 node in the list, so your argument is invalid. If you bother to even look at the visualization given, it even shows in the picture how a Node is added when there are nodes in the list so why are you talking about the list being empty when the obvious assumption is that the list is not empty.

In fact, all your arguments are invalid, its comprehensive enough for anyone who wants to understand the concept of how a link list insert and delete a node in the link list.

If you understand the meaning of what a concept tutorial vs spoonfeed tutorial means, that you got something.A linked list is a data structure that can store an indefinite amount of items. These items are connected using pointers in a sequential manner. There are two types of linked list; singly-linked list, and doubly-linked list.

In a singly-linked list, every element contains some data and a link to the. A Memory Allocator. by Doug Lea [A German adaptation and translation of this article appears in unix/mail December, This article is now out of date, and doesn't reflect details of current version of malloc.].

Jul 02,  · 6. Write a Program to convert a binary tree into a doubly linked list? (solution) This problem is opposite of question 25 where you need to write a program to convert a double linked list to the balanced binary tree. Jul 02,  · 6.

Write a Program to convert a binary tree into a doubly linked list? (solution) This problem is opposite of question 25 where you need to write a program to convert a double linked list to the balanced binary tree.

Write a program that maintains library shop stock using link list. Provide below facility in program 1) Insert book details 2) Purchase 3) Sale. We strongly recommend to refer following post as a prerequisite of this post.

Linked List Introduction Inserting a node in Singly Linked List. A Doubly Linked List (DLL) contains an extra pointer, typically called previous pointer, together with next pointer and data which are there in singly linked list.. Following is representation of a DLL node in C language.

Stack (abstract data type) - Wikipedia