计算机科学及编程导论在 MIT 的课程编号是 6.00.1,是计算机科学及工程学院的经典课程。之前,课程一直使用 Scheme 作为教学语言,不过由于 Python 简单、易学等原因,近年来已经改用 Python 作为教学语言了。(更多介绍

最初知道这个课程的时候大概是在 2014 年,对于做事拖沓的我,这门课程已经从低清随堂录制变成了 edX 平台的一门 高清的 MOOC,转眼间已经大三,希望自己能够完成自己曾经定下的计划。以下是在我在学习本课程时的一些笔记,在此与大家共享、共勉。

What does a computer do?

  • Fundamentally a computer:

    • Performs some calculations
    • Remembers results
  • What calculations?

    • Built in primitives
    • Creating our own methods of calculating

Simple calculations are not enough, so good algorithm design also needed to accomplish a task.

Despite its speed and storage, a computer does have limitations

  • Some problems still too complex
  • Some problems are fundamentally impossible to computer (e.g. Turing’s Halting Problem)

Knowledge

  • Declarative
  • Imperative (likes a recipe, “how-to”)

Computers

  • Fixed-program computers (earliest computers) To solve specific problems
    • Atanasoff (1941) - linear equations
    • Turing bombe
  • Stored-program computers A basic machine architecture
  • Program is a recipe. Each programming language provides a set of primitive operations.
  • Given a fixed set of primitives, a good programmer can program anything.
  • Anything you can do with a language, you can do with another.

About python

  • High(✅) vs. Low
  • General(✅) vs. Targetted
  • Interpreted(✅) vs. Compiled

Aspects of languages & Common Errors

AspectsDescription
Primitive constructsnumbers, strings, simple operators
Syntaxwhich strings of charactres and symbols are well-formed
Static semanticswhich syntactically valid strings have a meaning
Full semanticswhat is the meaning associated with a syntactically correct string of symbols with no static semantic errors
  • 语法用来描述语言中,什么表述是合法的。
  • 静态语义表示什么程序是有意义的,哪种表达是有意义的。
  • 完整语义即程序想达到什么目的,运行程序会产生什么效果。

Goal

  • Learn the syntax and semantics of a programming language.
  • Learn how to use those elements to translate “recipes” for solving a problem into a form that the computer can use to do the work for us.
  • Computational modes of thought enable us to use a suite of methods to solve problems.

References