Introduction to Data Structure
Lecture 1
1.1 INTRODUCTION Data structure is the branch of computer science that unleashes the knowledge of how the data should be organized, how the flow of data should be controlled and how a data structure should be designed and implemented to reduce the complexity and increase the efficiency of the algorithm. The theory of structures not only introduces the data structures, but also helps to understand and use the concept of abstraction, analyze problems step by step and develop algorithms to solve real world problems. Thus it enables various data structures like stacks, queue, linked list, trees and graphs. Effective use of principles of data structures increases efficiency of algorithms to solve problems like searching, sorting, populating and handling voluminous data. 1.2 Basic Terminology of Data Organization Data: The term data means a value or set of values. For example, marks of students, figures obtained during exit polls etc. The data is stored in the memory of computer. Different models are used to organize data in the memory. For example, the model used to organize the data in main memory are collectively referred to as data structures, whereas the different models used to organize data in the secondary memory are collectively referred to as file structures. Data item:- A data item means a single unit of values. For example, roll number, name, address etc. Entity: Entity is something that has certain qualities, characteristics, properties or attributes that may contain some values. For example, Student is an entity. The attributes of student may be roll number, name, address, etc, The values of these attributes may be 100, Ram, House No. 133-A, Pragati Vihar, Delhi. Entity Set: An entity set is a group of or set of similar entities. For example, employees of an organization, students of a class etc. Information: When the data is processed by applying certain rules, new processed data is called information. The data are not useful for decision
1.1 INTRODUCTION Data structure is the branch of computer science that unleashes the knowledge of how the data should be organized, how the flow of data should be controlled and how a data structure should be designed and implemented to reduce the complexity and increase the efficiency of the algorithm. The theory of structures not only introduces the data structures, but also helps to understand and use the concept of abstraction, analyze problems step by step and develop algorithms to solve real world problems. Thus it enables various data structures like stacks, queue, linked list, trees and graphs. Effective use of principles of data structures increases efficiency of algorithms to solve problems like searching, sorting, populating and handling voluminous data. 1.2 Basic Terminology of Data Organization Data: The term data means a value or set of values. For example, marks of students, figures obtained during exit polls etc. The data is stored in the memory of computer. Different models are used to organize data in the memory. For example, the model used to organize the data in main memory are collectively referred to as data structures, whereas the different models used to organize data in the secondary memory are collectively referred to as file structures. Data item:- A data item means a single unit of values. For example, roll number, name, address etc. Entity: Entity is something that has certain qualities, characteristics, properties or attributes that may contain some values. For example, Student is an entity. The attributes of student may be roll number, name, address, etc, The values of these attributes may be 100, Ram, House No. 133-A, Pragati Vihar, Delhi. Entity Set: An entity set is a group of or set of similar entities. For example, employees of an organization, students of a class etc. Information: When the data is processed by applying certain rules, new processed data is called information. The data are not useful for decision