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?
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Fundamentally a computer:
- Performs some calculations
- Remembers results
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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
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Fixed-program computers (earliest computers)
To solve specific problems- Atanasoff (1941) - linear equations
- Turing bombe
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Stored-program computers
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Program is a recipe. Each programming language provides a set of primitive operations.
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Given a fixed set of primitives, a good programmer can program anything.
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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
Aspects | Description |
---|---|
Primitive constructs | numbers, strings, simple operators |
Syntax | which strings of charactres and symbols are well-formed |
Static semantics | which syntactically valid strings have a meaning |
Full semantics | what 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.