Find the second last node of a linked list in single traversal
Show
Given a linked list. The task is to find the second last node of the linked list using a single traversal only.
Recommended: Please try your approach on {IDE} first, before moving on to the solution. The idea is to traverse the linked list following the below approach:
Below is the implementation of the above approach: Program for n’th node from the end of a Linked List
Given a Linked List and a number n, write a function that returns the value at the n’th node from the end of the Linked List. Recommended: Please solve it on “PRACTICE” first, before moving on to the solution. Method 1 (Use length of linked list) Below is the implementation of the above approach: inserting a node at the end of a linked listThe new node will be added at the end of the linked list. Deletion in singly linked list at the endThere are two scenarios in which, a node is deleted from the end of the linked list.
Types of Linked List and Operation on Linked ListIn the previous blog, we have seen the structure and properties of a Linked List. In this blog, we will discuss the types of a linked list and basic operations that can be performed on a linked list. Types of Linked ListFollowing are the types of linked list
Singly Linked ListA Singly-linked list is a collection of nodes linked together in a sequential way where each node of the singly linked list contains a data field and an address field that contains the reference of the next node. The structure of the node in the Singly Linked List is The nodes are connected to each other in this form where the value of the next variable of the last node is NULL i.e. next = NULL, which indicates the end of the linked list. Doubly Linked ListA Doubly Linked List contains an extra memory to store the address of the previous node, together with the address of the next node and data which are there in the singly linked list. So, here we are storing the address of the next as well as the previous nodes. The following is the structure of the node in the Doubly Linked List(DLL): The nodes are connected to each other in this form where the first node has prev = NULL and the last node has next = NULL. Advantages over Singly Linked List-
Disadvantages over Singly Linked List-
Circular Linked ListA circular linked list is either a singly or doubly linked list in which there are no NULL values. Here, we can implement the Circular Linked List by making the use of Singly or Doubly Linked List. In the case of a singly linked list, the next of the last node contains the address of the first node and in case of a doubly-linked list, the next of last node contains the address of the first node and prev of the first node contains the address of the last node. Advantages of a Circular linked list
Disadvantages of Circular linked list
Basic Operations on Linked List
We will see the various implementation of these operations on a singly linked list. Following is the structure of the node in a linked list: Linked List TraversalThe idea here is to step through the list from beginning to end. For example, we may want to print the list or search for a specific node in the list. The algorithm for traversing a list
Linked List node InsertionThere can be three cases that will occur when we are inserting a node in a linked list.
Insertion at the beginning Since there is no need to find the end of the list. If the list is empty, we make the new node as the head of the list. Otherwise, we we have to connect the new node to the current head of the list and make the new node, the head of the list. Insertion at end We will traverse the list until we find the last node. Then we insert the new node to the end of the list. Note that we have to consider special cases such as list being empty. In case of a list being empty, we will return the updated head of the linked list because in this case, the inserted node is the first as well as the last node of the linked list. Insertion after a given node We are given the reference to a node, and the new node is inserted after the given node. NOTE: If the address of the prevNode is not given, then you can traverse to that node by finding the data value. Linked List node DeletionTo delete a node from a linked list, we need to do these steps
In the deletion, there is a special case in which the first node is deleted. In this, we need to update the head of the linked list. Linked List node SearchingTo search any value in the linked list, we can traverse the linked list and compares the value present in the node. bool searchLL(Node head, int val) { Node temp = head // creating a temp variable pointing to the head of the linked list while( temp != NULL) // traversing the list { if( temp.data == val ) return true temp = temp.next } return false }Linked List node UpdationTo update the value of the node, we just need to set the data part to the new value. Below is the implementation in which we had to update the value of the first node in which data is equal to val and we have to set it to newVal. void updateLL(Node head, int val, int newVal) { Node temp = head while(temp != NULL) { if( temp.data == val) { temp.data = newVal return } temp = temp.next } }Suggested Problems to solve in Linked List
Happy coding! Enjoy Algorithms. Linked List Operations: Traverse, Insert and DeleteIn this tutorial, you will learn different operations on a linked list. Also, you will find implementation of linked list operations in C/C++, Python and Java. There are various linked list operations that allow us to perform different actions on linked lists. For example, the insertion operation adds a new element to the linked list. Here's a list of basic linked list operations that we will cover in this article.
Before you learn about linked list operations in detail, make sure to know about Linked List first. Things to Remember about Linked List
In all of the examples, we will assume that the linked list has three nodes 1 --->2 --->3 with node structure as below: struct node { int data; struct node *next; }; |