CS211Data Structures

Sami Rollins

srollins@mtholyoke.edu

Fall 2004

Introduction

• Course Website

• Syllabus

• Academic Dishonesty

• Tentative Calendar

Administrative Information

• Class web page

http://www.mtholyoke.edu/courses/srollins/cs101/

Assignments

• Reading – Chapter 1

• Homework 0 – due Monday

Computer Hardware

• Main memory

• Secondary memory

• CPU

• Input devices

• Output devices

Computer Software

• Operating system– Examples?

• Applications– Examples?

• How is a new application developed?

Computer Programs

• At the lowest level – machine instructions– 00000111000

• One step up – assembly language– ADD A

• More user friendly – high level languages– C = A + B;– Examples?

Translation

• High level language must be translated into a language the computer can understand

High-levelCode

CompilerMachineInstructions

Writing Programs

• Understand requirements

• Write an algorithm

• Implement your algorithm

• Test your code

What is an algorithm?

• A specific set of instructions

• An algorithm to make a PBJ sandwich?

Hello World/* * Name: Sami Rollins * Source file name: hello.c * My first "hello, world" program in C. */#include <stdio.h>

//the main functionint main (void){ //print the phrase printf("Hello, world!");

return(0);}

Errors

• You WILL have errors in your programs• Syntax Errors

– Compiler doesn’t understand code– Ex. – printf(Hello, world!”);– Sometimes error messages don’t match problem

• Logic– Program runs, but doesn’t do what you want– Ex. – printf(“Hell, world!”);– Can be hard to track down