=CSC151 2007S, Class 01: An Introduction to Algorithms=

Admin:
* TWO HANDOUTS BY FRONT DOOR!
* Sam will not be available during office hours today.
* Homework for tomorrow:
  * Introductory survey (distributed in class)
  * Reading on Linux (available on the Web; URL in survey)

Overview:
* Preliminaries
* Introduction: What is CS?
* Exercise: Drawing smileys.

==Preliminaries==

* Get a sticker and handouts
* Hi, I'm Sam
* That's your class mentor, Max
* Attendance

==What is computer science?==

* STUDENT RESPONSES FOLLOW
* CS = Programming 
  * Also knowing hardware and the inside of computers
  * Also knowing language
* CS = Ways to make a computer do what you want
* Science = the study of the world around us
  * Including modeling it with mathematical equations [maybe not]
  * Study includes investigation
* Scientists study the world using "the scientific method"
  * Ask a question
  * Prove or disprove it
  * Experimentation!
  * Observe + Notice patterns + Form hypothesis + Design experiment
    + Conduct the experiment + Analyze the data + UPDATE HYPOTHESIS
* Perhaps CS is not a science
  * But we can form some hypotheses: "If I press an A key, an A will appear on the screen"
  * That's not a very interesting hypothesis
  * Although some aspects of CS use the scientific method, the scientific
    method is not our primary approach
* Programming is also not the primary approach (or goal) of CS

Sam's common definition of CS:
  Computer science is the study of algorithms and data structures
  Algorithms = instructions for solving a problem
  Data structures = techniques for organizing data/information
  
In the end, most algorithms end up being expressed as programs

In this class:
* Design and analyze algorithms
* Express algorithms on the computer
* In a language called Scheme

==Laboratory Exercise==

(Note: Drawings take place on the physical whiteboard, and are not
 reproduced here.)

Why are we doing this exercise?
* To give you experience writing instructions
* To give us a starting point for discussions of writing instructions
* To reveal an important point: The kinds of instructions you write
  depend strongly on the basic operations you can rely on

Some observations

* Specificity helps
* Sometimes you have to improvise
* It helps to watch what's happening and update your instructions
  as you go
  * And don't always expect to write correct instructions the first
    time (or the second time) (or the third time) (or the six hundred
    and twenty third time)
* Working with others helps!