1 Introduction
“Computers are to computer science what telescopes are to astronomy.”
– E. Dijkstra
1.1 Objectives
Learn how to solve problems
Learn what computer scientists study
Understand and analyze some standard algorithms
Understand the form and function of various data structures
Learn how to implement them in Python
Learn to write bug-free and efficient code
How to write pseudo-code and analyze them on a whiteboard
1.2 What is a computer?
A machine that stores and manipulates information under the control of a changeable program.
Can computers do everything?
Not everything. Things that need infinite steps are not suitable for computers. For example, computers can not represent (without any approximation) the irrational numbers.
1.3 What is computer science
It is not the study of computers!!
“Computers are to computer science what telescopes are to astronomy.” – E. Dijkstra
What can be computed?
How can something be computed?
a recipe of computing something is called an algorithm
Making computations more efficient
1.4 Hardware
1.5 Programming Languages
Why do we need another language for speaking to computers?? > our languages are not precise
Computer semantics, on the other hand, are very precise
Coding the process of writing an algorithm in a programming language
1.6 Do computers really understand a programming language?
No!!
Computer hardware can only understand a very low-level language, known as machine language
Why not to learn machine language?
machine instructions are barely human-readable
they are not portable
1.7 High-level to Low-level
1.8 Interpreter
