Rabu, 10 Februari 2010

Data Structures

Reading Material
Data Structures and algorithm analysis in C++
Summary
  • Introduction to Data Structures
  • Selecting a Data Structure
  • Data Structure Philosophy
  • Goals of this Course
  • Array
  • List data structure
Welcome to the course of data structure. This is very important subject as the topics covered in it will be encountered by you again and again in the future courses. Due to its great applicability, this is usually called as the foundation course. You have already studied Introduction to programming using C and C++ and used some data structures. The focus of that course was on how to carry out programming with the use of C and C++ languages besides the resolution of different problems. In this course, we will continue problem solving and see that the organization of data in some cases is of immense importance. Therefore, the data will be stored in a special way so that the required result should be calculated as fast as possible.

Following are the goals of this course:
  • Prepare the students for (and is a pre-requisite for) the more advanced material students will encounter in later courses.
  • Cover well-known data structures such as dynamic arrays, linked lists, stacks, queues, trees and graphs.
  • Implement data structures in C++
You have already studied the dynamic arrays in the previous course. We will now discuss linked lists, stacks, queues, trees and graphs and try to resolve the problems with the help of these data structures. These structures will be implemented in C++ language. We will also do programming assignments to see the usage and importance of these structures.

Senin, 08 Februari 2010

KEY DATA COMMUNICATION TERMINOLOGY

  • Link: connects adjacent nodes Wires, Cables, Any thing that physically connects two nodes
  • Path: end-to-end route within a network
  • Circuit: the conduit over which data travels
  • Packetzing: dividing messages into fixed-length packets prior to transmission over a network’s communication media
  • Routing: determining a message’s path from sending to receiving nodes
  • The transmission medium may itself be a network, so route needs to be specified
Network
“A NETWORK is a set of devices (Nodes) connected by Communication Links”
  • Node: Can be a Computer, Printer or any other device capable of sending or receiving
  • The links connecting Nodes are called COMMUNICATION CHANNELS Networks- Why we need them?
Networks- Why we need them?
It is often impractical for devices to be directly connected for two major reasons:
  • The devices are very far apart. They are expensive to connect just two devices with one in Lahore and other in Islamabad
  • Large set of devices would need impractical number of connections e .g. Telephone Lines in the world and all the computers owned by a single organization
Solution to the Problem=Networks
  • Solution is to connect all devices to a central system known as a NETWORK in which all terminals or computers share the links.
  • Two Main Classifications of the Networks
  • LANS
  • WANS
DISTRIBUTED PROCESSING
  • Instead of a single large machine being responsible for all aspects of a process ,each separate computer handles a subset of the task
  • Example – Project Given as a part of the Course
  • Example – Office Work
Advantages of Distributed Processing
  • Security
A system designer can limit the kind of interaction that a given user can have with
the entire system.
  • For example : Bank’s ATM
  • Distributed Data bases
No one system need to provide storage capacity for the entire database
  • For example WWW gives user access to pages stored anywhere on Internet
  • Faster Problem Solving
Multiple computers working on a problem can solve a problem faster than a
computer working alone
  • Security through Redundancy
Multiple computers running the same program provide security through redundancy
If one computer's hardware breaks down others cover up
  • Collaborative Processing
Both multiple computers and multiple users can interact for a task