Data Structures

Lecture 1: Introduction

Azhar Maqsood NUST Institute of Information Technology (NIIT)

Administrative

 Instructor: Azhar Maqsood    

[email protected]

Extension: 136 Academic Block 2, Faculty Office Web Address :

http://www.niit.edu.pk/~azhar

 Consulting hours:   Tuesdays and Thursdays Depends on your schedule  Email me and get in touch if in need  Regularly check course folder in FileSvr and My website

Course Contents

 Data Types  Overview, Introductory concepts   Data Types, meaning and implementation Abstract data types (ADT)   Arrays (revisited) Structures  Linked Lists  Stacks (recursion)  Queues  Trees (traversals, implementation)

Course Contents

 Binary Trees  Indexing Methods  Hashing  Binary Search Trees  Balanced Search Trees  (AVL Tree) Adelson-Velskii-Landis  Heaps  Splay Trees  Graphs, adjacency matrices and lists

Text book

 “Data structures using C and C++”, Yedidyah Langsam, Moshe J Augenstein and Aaron M. Tenenbaum, 2 ed, 2002  Reference Books: • D. Wood: “Data structures, algorithms and performance”, Addison-Wesley, 1993 • • • C++ Data Structures by Nell Dale and David Teague http://www.brpreiss.com/books/opus4/html/book.html

Any other book on Data Structures

Assignment Policy

 DO NOT copy assignments  Both of the copy cases will be graded

zero

 Submission time will be 1500 hrs on the due date  NO credit on

LATE

submission of any deliverable.  No excuse of USB/Floppy/email servers not working  Sorry! No Exceptions

 OHT’s  Quizzes  Assignments  Project  Final Test

Weightage

30% (15 +15) 10% 10% 5% 45%  Minimum Quizzes : 5-6 (Unannounced)  Assignments : 1 Every 3 weeks

Honor Code

 Dishonesty will NOT be tolerated.  Will result in zero marks in the corresponding work

Lets start the course!

Why Study?

 Designed to develop students understanding the impact of

structuring data to achieve efficiency

of a solution to a problem  After completion you will be familiar with important and most often used data structuring techniques.

 It will enable you to understand the manner in which data is organized and presented later.

Objectives of the course

 Present in a systematic fashion the most commonly used data structures, emphasizing their abstract properties.

 Discuss typical algorithms that operate each kind of data structure, and analyze their performance.

 Compare different Data Structures for solving the same problem, and choose the best

Abstract Data Type ADT

 A data type whose properties (domain and operations) are specified independently of any particular implementation  ADT is a mathematical model which gives the a set of utilities available to the user but never states the details of its implementation.

 In OO-Programming a Class is an ADT

Data Structures: Definition

 A collection of data elements whose organization is characterized by accessing operations that are used to store and retrieve the individual data elements;  The logical arrangement of data as used by a system for data management; a representation of a data model in computer form

Data Structures: More specifically

 A data structure is a way of grouping fundamental types (like integers, floating point numbers, and arrays) into a bundle that represents some identifiable thing.

 For example, a matrix may be thought of as the bundle of the number of rows and columns, and the array of values of the elements of the matrix. This information must be known in order to manipulate the matrix.

 C introduced the struct for declaring and manipulating data structures. C++ extended the struct to a class

Goals of Data structures

 Identify and develop useful mathematical entities and operations and to determine what classes of problems can be solved by using these entities and operations.

 Determine representation of those abstract entities and to implement the abstract operation on these concrete representations.

A Real Life Example

Electronic Phone Book Contains different

DATA

: - names - phone number - addresses Need to perform certain

OPERATIONS

: - add - delete - look for a phone number - look for an address

How to organize the data so to optimize the efficiency of the operations

        

Lisa Michele John 110 622-9823 112-4433 75 Bronson Paola

The first Data Structure

 An Array!

Word about Arrays!

 Lets Get Started:  Arrays are data structures   Finite Contiguous   Fast Direct Access   All elements of same data type  (Can be based upon primitive or ADT) Insertion / Deletion ??? HOW?? 

Arrays

 How to Input arrays  How to process arrays  How to insert an item in an array  How to delete an item from an array  How to pass an array

Array

2 3 7 8 How to add 4 2 3 4 7 8 How to add 1 in the array?

Not possible