CS50 Introduction to Computer Science

Damon Jung
Aug 25, 2017 · 7 min read

MOOC Platform edX offers a free, great, and historic computer science course that Harvard University presents. It’s very well known for a passionate professor David J. Malan. He explains this difficult concept of computer science very easily.

Basic algorithm, data structure, image processing, cryptography, digital forensic, web programming, SQL, Meshup with Google API, and etc. You will learn these essential, broadly applicable skills and knowledge. It’s consist of 11 week courses and you can accomplish the course if you completing it at the end of the year. It will be challenging if you don’t have some programming experiences, but if you could manage to finish the course on your own, you will definitely get to know what Computational Thinking is. It’s really good course actually.

It’s so famous that even in Yale, there’s CS50 too. How lucky it is to have this kind of lecture for free on the internet?

He leaped off the thick phone book by half to explain Binary Search concept. You can learn it by heart !. Personally I was really charmed by this scene and it made me actually finish this course.

1, 2, 4, 8, 16, 32, 64, 128… if you’ve learnt binary calculation or if you have a computer science / engineering background, you can guess what this is about. He tries to explain binary concept using those bulbs !

@Fun

[ 0 0 0 0 0 0 0 0 ] is 8 bits, so it’s 1Byte. A computer can only express decimal 8

[ 0 0 0 1 0 0 0 0 ] like this. He explains this job by turning on the fourth bulb.

There’s a limitation on Startcraft unit upgrade. The maximum is 255, because they declared the variable size as 1Byte.

Digging into programming further, it’s unsigned type so it doesn’t have a leading sign so it can express 255 including zero.

Well, this is for Korean reader but anyway, There is a game called Lineage 1.

If you had played this game in around late 90 or early 2000, you may know the highest armor rate was -127.

This is also because the variable size for this armor was defined as 1Byte. But this time it has the leading sign minus.

It is signed type. So it can express 127~-128. I don’t know why -127 is maximum there while it can go down to -128.

@Fun

In this scene, the professor tries to explain how Linked List works. People are pointing a person next to them. Guess what? it’s pointer concept. In my humble opinion, beginners for C will get to know pointer very easily with this lecture.

I paid $90 to get this certification, thinking that MOOC will someday be valued as much as the offline school.

This course has Facebook CS50 page. You can exchange information and solve problem and communicate with your colleagues. David J. Malan professor is active there too. I put up a post on this page and David commented me. I thought “ what an honor!! “ at first, but it wasn’t me who got this comment on this page. He just works lively here as well.

I strongly felt that MOOC is really good so I tried to find another computer engineering / science class but none of them matched to CS50. The grading system, the cloud IDE, supplement materials, advising steps, community are just incomparable.

If you are into computer science / engineering and have passion for learning, I will 4 thumbs up for this lecture.

CS50 Introduction to Computer Science (0) 2017.08.25


Originally published at geniusdm.tistory.com on August 25, 2017.

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