Data Structures Lecture 1: Introduction Azhar Maqsood NUST Institute of Information Technology (NIIT)

Administrative Instructor: Azhar Maqsood     Extension: 136   Academic Block 2, Faculty Office   Web Address : Consulting hours:   Tuesdays and Thursdays   Depends on your schedule 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  Adelson-Velskii-Landis  (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 “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 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/ servers not working Sorry! No Exceptions

Weightage OHT’s30% (15 +15) Quizzes10% Assignments10% Project5% Final Test45% 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 Lisa Michele John Bronson Paola 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

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

Array2378 How to add How to add 1 in the array? Not possible