This document provides an introduction to data structures and algorithms. It defines an algorithm as a set of steps to solve a problem and describes data structures as organized ways to store and access data. Common data structures include arrays, stacks, queues, linked lists, trees and graphs. Abstract data types define the fundamental operations on data objects in a data structure independently of their implementation. Linear data structures like arrays represent lists in one dimension while non-linear structures represent two-dimensional relationships. Stacks follow the last-in, first-out principle with push and pop operations, while queues are first-in, first-out. Selection of the appropriate data structure depends on the application.

1. INTRODUCTION TO DATA STRUCTURES AND ALGORITHM

2. Define : A Procedure or method or recipe or formula or set of steps that can be used by a computer for the solution of a problem It is a specific set of rules to obtain a definite output from specific inputs provide to the problem WHAT IS ALGORITHM ?

3. WHAT IS DATA STRUCTURE? 1. A Data structure is a particular way of storing and organizing data in a computer. So that it can be used efficiently. 2. Data structures deals with the study of methods, techniques and tools to organize or structure data

4. Different kinds of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks. For example, B-trees are particularly well-suited for implementation of databases , while compiler implementations usually use hash tables to look up identifiers.

5. Data structures are used in almost every program or software system. Data structures provide a means to manage huge amounts of data efficiently, such as large databases and internet indexing services. Usually, efficient data structures are a key to designing efficient algorithms

6. ABSTRACT DATA TYPES [ADT] WHAT IS DATA TYPES? A data type refers to the type of values that variables in a programming language hold. WHAT IS ADT? Abstract data type refers to the data objects (refers to the list of elements such as list of integers or list of alphabetical strings) which comprise the data structure, and their fundamental operations.

7. An ADT promotes data abstraction and focuses on what a data structure does rather than how it does

8. CLASSIFICATION OF DATA STRUCTURES DATA STRUCTURES Non-Linear Linked Sequential Linear Arrays Stacks Queues Priority queues Linked Lists Linked Stacks Linked Queues Trees Graphs

9. Linear data structures are unidimensional in structure and represent linear lists. Non-linear data structures are two-dimensional representation of data lists

10. ARRAYS

11. WHAT IS ARRAY? An array is an ADT whose objects are sequence of elements of the same types and the two operations performed on it are store and retrieve. STORE(list, i, e) RETRIEVE(list , i )

12. TYPES OF ARRAY One-dimensional A[1:5] Two dimensional B[1:3][1:4] Multi dimensional C[1:3][1:6][1:8]….

13. STACK

14. A stack is a last in, first out (LIFO) abstract data type and data structure. A stack can have any abstract data type as an element It is characterized by only three fundamental operations: push , pop and stack top . The push operation adds a new item to the top of the stack, or initializes the stack if it is empty.

15. If the stack is full and does not contain enough space to accept the given item, the stack is then considered to be in an overflow state. The pop operation removes an item from the top of the stack. A pop either reveals previously concealed items, or results in an empty stack, But if the stack is empty then it goes into underflow state (It means no items are present in stack to be removed).

16. The stack top operation gets the data from the top-most position and returns it to the user without deleting it. The same underflow state can also occur in stack top operation if stack is empty.

17. A stack is a restricted data structure , because only a small number of operations are performed on it . The nature of the pop and push operations also means that stack elements have a natural order. Elements are removed from the stack in the reverse order to the order of their addition: therefore, the lower elements are those that have been on the stack the longest.

18. Implementation of push operation on a stack Procedure PUSH(STACK,n,top,item) if(top=n) then STACK_FULL; else { top=top+1; STACK[top]=item; } end PUSH

19. Implementation of pop operation on a stack Procedure POP(STACK,top,item) if(top=0) then STACK_EMPTY; else { item=STACK[top]; top=top-1; } end POP

20. QUESTIONS ?

21. THANK YOU