Unit 3 dsa LINKED LIST
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The document discusses linked lists, which are a linear data structure consisting of nodes connected to each other via pointers. Each node contains data and a pointer to the next node. There are several types of linked lists including singly linked lists where each node has a next pointer, doubly linked lists where each node has next and previous pointers, and circular linked lists where the last node points to the first node. The document covers terminology, advantages and disadvantages, operations, and implementations of different types of linked lists such as dynamic vs static memory allocation and uses in applications.
Unit 3 dsa LINKED LIST
- 1. Pune Vidyarthi Griha’s COLLEGE OF ENGINEERING, NASHIK – 3. “Linked List” By Prof. Anand N. Gharu (Assistant Professor) PVGCOE Computer Dept. 04 August 2019 . 1
- 2. Concept, Comparison of sequential and linked organizations, Primitive operations, Realization of Linked Lists, Realization of linked list using arrays, Dynamic Memory Management, Linked list using dynamic memory management, Linked List Abstract Data Type, Linked list operations, Head pointer and header node, Types of linked list- Linear and circular linked lists, Doubly Linked List and operations, Circular Linked List, Singly circular linked list, Doubly circular linked list, Polynomial Manipulations - Polynomial addition, Multiplication of two polynomials using linked list. Generalized Linked List (GLL) concept, representation of polynomial and sets using GLL. Case Study- GarbageCollection.2 UNIT – 2 SYLLABUS
- 3. “ Linked List is a very commonly used linear data structure which consists of group of nodes in a sequence. Each node holds its own data and the address of the next node hence forming a chain like structure.” Linked Lists are used to create trees and graphs. 3 INTRODUCTION OF LINKED LIST
- 4. Fig: 1 Data Organization 4
- 5. Fig: 2 (a): A linked list of nelements Fig: 2 (b) : A linked list ofweekdays 5
- 6. Advantages of Linked Lists They are a dynamic in nature which allocates the memory when required. Insertion and deletion operations can be easily implemented. Stacks and queues can be easily executed. Linked List reduces the access time. Disadvantages of Linked Lists The memory is wasted as pointers require extra memory for storage. No element can be accessed randomly; it has to access each node sequentially. Reverse Traversing is difficult in linked list. 6 INTRODUCTION OF LINKED LIST
- 7. Applications of Linked Lists 1. Linked lists are used to implement stacks, queues, graphs, etc. 2. Linked lists let you insert elements at the beginning and end of the list. 3. In Linked Lists we don't need to know the size in advance. 7 INTRODUCTION OF LINKED LIST
- 8. Node an item in a linked list. Each node contains a piece of list data and the location of the next node (item). Link (of a node) the location of the next node. head node first node in a linked list head pointer points to the head node. Null pointer there is no need in it (linked list is empty) 8 TERMINOLOGIES OF LINKED LIST
- 9. PROF. ANAND GHARU 9 DIFFERENCE BETWEEN SEQUENTIAL AND LINKED ORGANIZATION
- 10. PROF. ANAND GHARU 10 LINKED LIST PRIMITIVE OPERATION Basic Operations Following are the basic operations supported by a list. Insertion − Adds an element at the beginning of the list. Deletion − Deletes an element at the beginning of the list. Display − Displays the complete list. Search − Searches an element using the given key. Delete − Deletes an element using the given key.
- 11. PROF. ANAND GHARU 11 DYNAMIC MEMORY MANAGEMENT “ Dynamic Memory Allocation means memory which can be allocated or deallocated as per requirement at run time” Importance of memory allocation : no need to initially occupy large amount of memory. Memory can be allocated or deallocated as per need. It avoid wastage of memory. We can free the memory by de-allocating it using free( ).
- 12. PROF. ANAND GHARU 12 FUNCTION DYNAMIC MEMORY ALLOCATION
- 13. PROF. ANAND GHARU 13 COMPARE Malloc( ) AND Calloc( ) MEMORY
- 14. PROF. ANAND GHARU 14 Representation of Linked list Realization stands for Representation of Linked List A linked list can be represented in two ways : 1. Dynamic representation of linked list 2. Station representation of linked list
- 15. PROF. ANAND GHARU 15 Representation of Linked list Dynamic Representation of linked list :
- 16. PROF. ANAND GHARU 16 Representation of Linked list Static Representation of linked list :
- 17. PROF. ANAND GHARU 17 Linked list Abstract Data Type “Linked List is an Abstract Data Type (ADT) that holds a collection of Nodes,the nodes can be accessed in a sequential way. Linked List doesn’t provide a random access to a Node.” Usually, those Nodes are connected to the next node and/or with the previous one, this gives the linked effect. When the Nodes are connected with only the next pointer the list is called Singly Linked List and when it’s connected by the next and previous the list is called Doubly Linked List.
- 18. PROF. ANAND GHARU 18 Linked list Abstract Data Type ADT — Interface The Linked List interface can be implemented in different ways, is important to have operations to insert a new node and to remove a Node: ADT Operation : Create – Creation of linked list Traversal – it can be traversed Search – Data can be compare with data to be search. Destroy – Free the memory
- 19. PROF. ANAND GHARU 19 TYPES OF LINKED LIST There are 3 different implementations of Linked List available, they are: 1. Linear/Singly Linked List 2. Doubly Linked List 3. Circular Linked List
- 20. PROF. ANAND GHARU 20 LINEAR/SINGLY LINKED LIST “ A linked list in which every node has one link field, to provide information about where the next node of list is, is called as singly linkedlist ”
- 21. PROF. ANAND GHARU 21 LINEAR/SINGLY LINKED LIST Singly linked list is a basic linked list type. Singly linked list is a collection of nodes linked together in a sequential way where each node of singly linked list contains a data field and an address field which contains the reference of the next node. Singly linked list can contain multiple data fields but should contain at least single address field pointing to its connected next node.
- 22. PROF. ANAND GHARU 22 ADVANTAGES OF SINGLY LINKED LIST 1. Singly linked list is probably the most easiest data structure to implement. 2. Insertion and deletion of element can be done easily. 3. Insertion and deletion of elements doesn't requires movement of all elements when compared to an array. 4. Requires less memory when compared to doubly, circular or doubly circular linked list. 5. Can allocate or deallocate memory easily when required during its execution. 6. It is one of most efficient data structure to implement when traversing in one direction is required.
- 23. PROF. ANAND GHARU 23 DISADVANTAGES OF SINGLY LINKED LIST 1. It uses more memory when compared to an array. 2. Since elements are not stored sequentially hence requires more time to access each elements of list. 3. Traversing in reverse is not possible in case of Singly linked list when compared to Doubly linked list. 4. Requires O(n) time on appending a new node to end. Which is relatively very high when compared to array or other linked list.
- 24. PROF. ANAND GHARU 24 SINGLY LINKED LIST OPERATION 1. Creation 2. Insertion 3. Deletion 4. Searching 5. Display
- 25. PROF. ANAND GHARU 25 DOUBLY LINKED LIST In doubly linked list, each node has two link fields to store information about who is the next and also about who is ahead of thenode Hence each node has knowledge of its successor and also its predecessor. In doubly linked list, from every node the list can be traversed in both the directions.
- 26. PROF. ANAND GHARU 26 DOUBLY LINKED LIST Doubly Linked List is a variation of Linked list in which navigation is possible in both ways, either forward and backward easily as compared to Single Linked List. Following are the important terms to understand the concept of doubly linked list. Link − Each link of a linked list can store a data called an element. Next − Each link of a linked list contains a link to the next link called Next. Prev − Each link of a linked list contains a link to the previous link called Prev. LinkedList − A Linked List contains the connection link to the first link called First and to the last link called Last.
- 27. PROF. ANAND GHARU 27 BASIC OPERATION OF DLL Following are the basic operations supported by a list. Insertion − Adds an element at the beginning of the list. Deletion − Deletes an element at the beginning of the list. Insert Last − Adds an element at the end of the list. Delete Last − Deletes an element from the end of the list. Insert After − Adds an element after an item of the list. Delete − Deletes an element from the list using the key. Display forward − Displays the complete list in a forward manner. Display backward − Displays the complete list in a backward manner.
- 28. PROF. ANAND GHARU 28 ADVANTAGES OF DOUBLY LINKED LIST 1) A DLL can be traversed in both forward and backward direction. 2) The delete operation in DLL is more efficient if pointer to the node to be deleted is given. 3) We can quickly insert a new node before a given node. In singly linked list, to delete a node, pointer to the previous node is needed. To get this previous node, sometimes the list is traversed. In DLL, we can get the previous node using previous pointer.
- 29. PROF. ANAND GHARU 29 DISADVANTAGES OF DOUBLY LINKED LIST 1) Every node of DLL Require extra space for an previous pointer. It is possible to implement DLL with single pointer though 2) All operations require an extra pointer previous to be maintained. For example, in insertion, we need to modify previous pointers together with next pointers. For example in following functions for insertions at different positions, we need 1 or 2 extra steps to set previous pointer.
- 30. PROF. ANAND GHARU 30 SINGLY CIRCULAR LINKED LIST “Circular Linked List is a variation of Linked list in which the first element points to the last element and the last element points to the first element. Both Singly Linked List and Doubly Linked List can be made into a circular linked list”.
- 31. PROF. ANAND GHARU 31 CIRCULAR LINKED LIST Circular linked list are mostly used in task maintenance in operating systems. There are many examples where circular linked list are being used in computer science including browser surfing where a record of pages visited in the past by the user, is maintained in the form of circular linked lists and can be accessed again on clicking the previous button.
- 32. PROF. ANAND GHARU 32 BASIC OPERATION OF CLL Following are the important operations supported by a circular list. insert − Inserts an element at the start of the list. delete − Deletes an element from the start of the list. display − Displays the list.
- 33. PROF. ANAND GHARU 33 ADVANTAGES OF CIRCULAR LINKED LIST 1. Some problems are circular and a circular data structure would be more natural when used to represent it. 2. The entire list can be traversed starting from any node (traverse means visit every node just once) 3. fewer special cases when coding(all nodes have a node before and after it)
- 34. PROF. ANAND GHARU 34 DISADVANTAGES OF CIRCULAR LINKED LIST 1. Circular list are complex as compared to singly linked lists. 2. Reversing of circular list is a complex as compared to singly or doubly lists. 3. If not traversed carefully, then we could end up in an infinite loop.
- 35. PROF. ANAND GHARU 35 DOUBLY CIRCULAR LINKED LIST “Circular Doubly Linked List has properties of both doubly linked list and circular linked list in which two consecutive elements are linked or connected by previous and next pointer and the last node points to first node by next pointer and also the first node points to last node by previous pointer”.
- 36. PROF. ANAND GHARU 36 BASIC OPERATION OF DOUBLY CIRCULAR LL
- 37. PROF. ANAND GHARU 37 ADVANTAGES OF CIRCULAR LINKED LIST 1. List can be traversed from both the directions i.e. from head to tail or from tail to head. 2. Jumping from head to tail or from tail to head is done in constant time O(1). 3. Circular Doubly Linked Lists are used for implementation of advanced data structures like Fibonacci Heap.
- 38. PROF. ANAND GHARU 38 DISADVANTAGES OF CIRCULAR LINKED LIST 1. It takes slightly extra memory in each node to accommodate previous pointer. 2. Lots of pointers involved while implementing or doing operations on a list. So, pointers should be handled carefully otherwise data of the list may get lost. Applications of Circular doubly linked list Managing songs playlist in media player applications. Managing shopping cart in online shopping
- 39. PROF. ANAND GHARU 39
- 40. A node will have 3 fields, which represent the coefficient and exponent of a term and a pointerto the next term 40 POLYNOMIAL MANIPULATIONS
- 41. E.x. For instance, the polynomial, say A = 6x7 + 3x5 + 4x3 + 12 would be stored as: 41 POLYNOMIAL MANIPULATIONS
- 42. Operation on Polynomial 42 Polynomial evaluation Polynomial addition Multiplication of two polynomials of sparse matrix using Representation linked list Linked list implementation of the stack Generalized linked list
- 45. GENERALIZED LINKED LIST 45 • “A generalized list, A, is a finite sequence of n > 0 elements, 1, ..., nwhere the i are either atoms or lists. The elements i, 1 i n which are not atoms are said to be the sublists of A.”
- 50. Representation of Polynomial using GLL 50
- 51. GARBAGE COLLECTION 51 garbage collection is the process of collecting all unused nodes and returning them to available space. This process is carried out in essentially two phases. In the first phase, known as the marking phase, all nodes in use are marked. In the second phase all unmarked nodes are returned to the available space list. This second phase is trivial when all nodes are of a fixed size. In this case, the second phase requires only the examination of each node to see whether or not it has been marked.
- 52. 52 THANK YOU !!!!! Blog : anandgharu.wordpress.com [email protected] PROF. ANAND GHARU 52
- 53. GARBAGE COLLECTION 53 If there are a total of n nodes, then the second phase of garbage collection can be carried out in O(n) steps. In this situation it is only the first or marking phase that is of any interest in designing an algorithm. When variable size nodes are in use, it is desirable to compact memory so that all free nodes form a contiguous block of memory. In this case the second phase is referred to as memory compaction. Compaction of disk space to reduce average retrieval time is desirable even for fixed size nodes. In this section we shall study two marking algorithms and one compaction algorithm.