Lecture 0 - Computational Thinking, Scratch

input -> [ black box ] -> output

How to represent input/output information?

• represent number
• represent characters/letters:
  • ASCII (8 bits)

A:65(01000001) 

• • Unicode(a superset of ASCII, 8/16/24/32 bits)

　　　　　　emoji ?? ：128514（11111011000000010）

• represent colors
  • RGB: every dot in an image is stored using three value

　　　　　　a shade of yellow: 72 73 33

　　　　　　every dot in an image is used three value

• • • animated GIF/videos

multiple images in the same file, one image fly past after another to create an illusion of moving

• represent music

　　　　　　maybe the note, the duration, the value

input -> [ algorithms ] -> output

The algorithm is a step-by-step process for solving a problem.

• functions: verbs or actions to tell computers what to do
• conditions
• Boolean expressions: one or zero questions
• loops
• variables
• threads
• events

CS50 2019

原文：https://www.cnblogs.com/lichtung/p/13066460.html