7 ms·

Algorithms by Jeff Erickson (2019)

377 points by kkwteh 4y ago

herpderperator 4y ago
Link should be updated to the HTTPS version: https://jeffe.cs.illinois.edu/teaching/algorithms/ https://jeffe.cs.illinois.edu/teaching/algorithms/
- hdjsbdusn 4y ago
  Why?
  - Supermancho 4y ago
    Because of how the most popular browser on the planet treats http and there's no downside to using https. Obvious.
    - dhhsbeb 4y ago
      But there is a downside, it uses more power. I don’t see the upside in this case, hence the question. It sounds like think so because it’s it’s what you’ve become accustomed to without questioning.
      - Supermancho 4y ago
        > But there is a downside, it uses more power. It's less power than loading a one more line of markup in the browser. Do you throttle the size of webpages in the interest of power? That's as ridiculous a "downside" as having to type one more letter. https has both practical tooling advantages and security advantages. Specifically, if you're in a network (or country) that is known for tampering with network traffic, https is a well tested preventative measure.
      - herpderperator 4y ago
        Because otherwise everyone can read and change what you're browsing without your knowledge. AES is hardware-accelerated on most machines.
  - n3t 4y ago
    For example because some ISPs inject ads or malware when using HTTP.
- dang 4y ago
  Ok, we've done that.
jacamera 4y ago
As a self-taught developer this book has been an incredibly valuable resource. I'm immensely grateful that resources like this exist freely on the internet.
- pm90 4y ago
  If you haven't reached out to Jeff, I would highly recommend sending him an email explaining how its impacted you. He is just an amazing person overall and loves to teach.
  - cinntaile 4y ago
    I think he's on HN, so there is a chance he'll see that post!
  - jacamera 4y ago
    I have not and that's a great idea. Thanks!
- jefferickson 4y ago
  Thanks for the kind feedback. I'm glad I could help!
azhenley 4y ago
Jeff was also very active on Academia.StackExchange, where he was invaluable in helping many early career faculty and PhD students, including myself. Nearly 97,000 reputation from more than 500 answers. His profile: https://academia.stackexchange.com/users/65/jeffe https://academia.stackexchange.com/users/65/jeffe
- therein 4y ago
  Also known to be the best Theory of Computation (373&374, they made changes) teacher in UIUC back in the day, potentially to this day.
- vmladenov 4y ago
  He’s also relatively active as u/jeffgerickson on r/UIUC. One of the best instructors I’ve had in my lifetime
anewpersonality 4y ago
A must read before any coding interview.
jason2323 4y ago
As an undergrad studying an algorithms, I didn't not find this book useful. Somehow it managed to confuse me more.
- adchari 4y ago
  To be fair, this book definitely doesn’t start from first principles since UIUC requires several classes before 374 (the class which uses this book). UIUC splits the data structures material into another hands-on class, and introduces discrete math and preliminary ideas about algorithm analysis and proving correctness in another course. On top of that, 374 only uses about half this textbook in conjunction with other notes about topics not covered in this book (mostly models of computation). The rest of the material in this textbook is used in 473, the elective advanced algorithms course. That’s not to say that your experience isn’t valid, but within the context it is primarily used in, it’s a very good additional resource to lecture content, which is more than can be said of most textbooks
  - Apocryphon 4y ago
    So not that dissimilar from CLRS, then. Despite its introductory title it is very dense and voluminous. Almost more like a graduate level reference. There really needs to be a text that captures the middle ground between CLRS and Grokking Algorithms and I guess this isn’t it.
    - eredengrin 4y ago
      I'm not familiar with Grokking Algorithms, but fwiw the most important prereq at UIUC for 374 is 173, which also happens to have a free textbook[1] written by another UIUC professor, Margaret Fleck. I consider it to be a high quality introduction to discrete math and have good memories of her as a professor as well. [1] https://mfleck.cs.illinois.edu/building-blocks/updates-fa2017//whole-book.pdf https://mfleck.cs.illinois.edu/building-blocks/updates-fa201...
      - Apocryphon 4y ago
O__________O 4y ago
Most notable prior HN posts: —- 1463 points|4 years ago|238 comments https://news.ycombinator.com/item?id=18805624 https://news.ycombinator.com/item?id=18805624 —- 595 points|1 year ago|152 comments https://news.ycombinator.com/item?id=26074289 https://news.ycombinator.com/item?id=26074289 ________________________ * All other prior posts: https://hn.algolia.com/?q=http%3A%2F%2Fjeffe.cs.illinois.edu%2Fteaching%2Falgorithms%2F https://hn.algolia.com/?q=http%3A%2F%2Fjeffe.cs.illinois.edu...
quantumduck 4y ago
Jeff also owns this domain that redirects to this book: algorithms.wtf
- nequo 4y ago
  Oh wow, that's very cool. Did he do this as a SEO hack or just as an easy-to-remember shortcut for his book? His illinois.edu page is the second hit for me for "algorithms wtf" in DuckDuckGo and the first hit in Google. There is a non-zero probability that I would find his book by searching for that. Edit: Sorry if this came across as disrespectful. I don't think that a SEO hack in this case is bad. If you put your care and attention into writing and revising a 472-page textbook, you want people to find it. There's nothing wrong with that.
  - quantumduck 4y ago
    I don't think Jeff cares about SEO. He was out probably looking for a simple domain and I'm sure algorithms.com, algorithms.org etc. were already taken. If I had to pick between say algorithms.me and algorithms.wtf, I'd definitely go with the second one, especially because students like me will remember it for life.
  - jrumbut 4y ago
    In the linked page he refers to it as a more memorable link and presents it as an easy way to comply with the terms of this book's CC license. "Oh you're looking for an algorithms textbook, have you tried..."
johnohara 4y ago
Family, pancakes and algorithms. In that order (no pun intended).
primitivesuave 4y ago
Jeff Erickson was my favorite professor at UIUC, and his ability to explain complex ideas in meaningful ways inspired my own journey as a computer science educator.
- pizza234 4y ago
  He also has a very interesting history: > I have the lowest undergraduate GPA (2.4/4.0) of any professor I've ever met with reference to https://3dpancakes.typepad.com/ernie/2005/03/re_phd_with_low.html https://3dpancakes.typepad.com/ernie/2005/03/re_phd_with_low....
  - dataflow 4y ago
    I love this quote: > I discovered (or remembered) that I was more interested in doing things RIGHT than doing them NOW, which is bad news in the software industry; this wasn't the place for me.
imadr 4y ago
The logo is "Khwarizmi" written in square kufic script, pretty cool
rg111 4y ago
Here are some books that I suggest to learn DSA properly: 1. A Common-Sense Guide to Data Structure and Algorithms from PragProg Bookshelf. Written in a very approachable manner with very good code. The best for self-learners. 2. Algorithms by Dasgupta, Papadimitriou, Vazirani (DPV). Very short and concise book- extremely well-written with a personality. Requires basic CS math. 3. Algorithm Design Manual by Skeina. Extremely approachable as well. Has 'battle stories' of algorithm usage. Good for self-learners. Links to problems in Leetcode is given. 4. CLRS is of course nice for a mathematically rigorous study.
- marai2 4y ago
  I'll second the recommendation above. For folks coming to algorithms for the first time I would recommend _Grokking Algorithms An illustrated guide for programmers and other curious people_ as a nice quick _tour_ of the field. And the _Common Sense Guide_ (mentioned above) as the next book. For complete beginners this book has the best simple explanations of algorithms I've read in any book (and I have a whole bunch of them).
- trenchgun 4y ago
  Why do you think Jeff Ericksons book is not hood for that?
  - jefferickson 4y ago
    Well, I can tell you why I think my book is not good for that — it isn't designed to be that! My book grew out of lecture notes that I wrote for my algorithms classes at Illinois. My students are almost exclusively juniors and seniors. In particular, they already have several semesters of programming experience, a full semester of discrete math, and a full semester of data structures (which includes things like sorting and searching and the basics of algorithm analysis). They are the audience I wrote the book for. Equivalently, I have very little experience teaching those prerequisite classes, which makes me the wrong person to write a textbook about that more foundational material! At a more basic level: Different people are going to find different sources more or less useful. Different authors are better matches for different readers' backgrounds, intuition, and needs. My book ain't gonna work for everyone, because no single book works for everyone. I'm not familiar with Common Sense Guide — thanks for the suggestion! — but the other books listed above are all fantastic (for different reasons, and for different audiences).

377 points by kkwteh 4y ago

Link should be updated to the HTTPS version: https://jeffe.cs.illinois.edu/teaching/algorithms/ https://jeffe.cs.illinois.edu/teaching/algorithms/

hdjsbdusn 4y ago
Why?
- Supermancho 4y ago
  Because of how the most popular browser on the planet treats http and there's no downside to using https. Obvious.
  - dhhsbeb 4y ago
    But there is a downside, it uses more power. I don’t see the upside in this case, hence the question. It sounds like think so because it’s it’s what you’ve become accustomed to without questioning.
    - Supermancho 4y ago
      > But there is a downside, it uses more power. It's less power than loading a one more line of markup in the browser. Do you throttle the size of webpages in the interest of power? That's as ridiculous a "downside" as having to type one more letter. https has both practical tooling advantages and security advantages. Specifically, if you're in a network (or country) that is known for tampering with network traffic, https is a well tested preventative measure.
    - herpderperator 4y ago
      Because otherwise everyone can read and change what you're browsing without your knowledge. AES is hardware-accelerated on most machines.
- n3t 4y ago
  For example because some ISPs inject ads or malware when using HTTP.
dang 4y ago
Ok, we've done that.

jacamera 4y ago

As a self-taught developer this book has been an incredibly valuable resource. I'm immensely grateful that resources like this exist freely on the internet.

pm90 4y ago
If you haven't reached out to Jeff, I would highly recommend sending him an email explaining how its impacted you. He is just an amazing person overall and loves to teach.
- cinntaile 4y ago
  I think he's on HN, so there is a chance he'll see that post!
- jacamera 4y ago
  I have not and that's a great idea. Thanks!
jefferickson 4y ago
Thanks for the kind feedback. I'm glad I could help!

azhenley 4y ago

Jeff was also very active on Academia.StackExchange, where he was invaluable in helping many early career faculty and PhD students, including myself. Nearly 97,000 reputation from more than 500 answers. His profile: https://academia.stackexchange.com/users/65/jeffe https://academia.stackexchange.com/users/65/jeffe

therein 4y ago
Also known to be the best Theory of Computation (373&374, they made changes) teacher in UIUC back in the day, potentially to this day.
vmladenov 4y ago
He’s also relatively active as u/jeffgerickson on r/UIUC. One of the best instructors I’ve had in my lifetime

anewpersonality 4y ago

A must read before any coding interview.

jason2323 4y ago

As an undergrad studying an algorithms, I didn't not find this book useful. Somehow it managed to confuse me more.

adchari 4y ago
To be fair, this book definitely doesn’t start from first principles since UIUC requires several classes before 374 (the class which uses this book). UIUC splits the data structures material into another hands-on class, and introduces discrete math and preliminary ideas about algorithm analysis and proving correctness in another course. On top of that, 374 only uses about half this textbook in conjunction with other notes about topics not covered in this book (mostly models of computation). The rest of the material in this textbook is used in 473, the elective advanced algorithms course. That’s not to say that your experience isn’t valid, but within the context it is primarily used in, it’s a very good additional resource to lecture content, which is more than can be said of most textbooks
- Apocryphon 4y ago
  So not that dissimilar from CLRS, then. Despite its introductory title it is very dense and voluminous. Almost more like a graduate level reference. There really needs to be a text that captures the middle ground between CLRS and Grokking Algorithms and I guess this isn’t it.
  - eredengrin 4y ago
    I'm not familiar with Grokking Algorithms, but fwiw the most important prereq at UIUC for 374 is 173, which also happens to have a free textbook[1] written by another UIUC professor, Margaret Fleck. I consider it to be a high quality introduction to discrete math and have good memories of her as a professor as well. [1] https://mfleck.cs.illinois.edu/building-blocks/updates-fa2017//whole-book.pdf https://mfleck.cs.illinois.edu/building-blocks/updates-fa201...
    - Apocryphon 4y ago

O__________O 4y ago

Most notable prior HN posts: —- 1463 points|4 years ago|238 comments https://news.ycombinator.com/item?id=18805624 https://news.ycombinator.com/item?id=18805624 —- 595 points|1 year ago|152 comments https://news.ycombinator.com/item?id=26074289 https://news.ycombinator.com/item?id=26074289 ________________________ * All other prior posts: https://hn.algolia.com/?q=http%3A%2F%2Fjeffe.cs.illinois.edu%2Fteaching%2Falgorithms%2F https://hn.algolia.com/?q=http%3A%2F%2Fjeffe.cs.illinois.edu...

quantumduck 4y ago

Jeff also owns this domain that redirects to this book: algorithms.wtf

nequo 4y ago
Oh wow, that's very cool. Did he do this as a SEO hack or just as an easy-to-remember shortcut for his book? His illinois.edu page is the second hit for me for "algorithms wtf" in DuckDuckGo and the first hit in Google. There is a non-zero probability that I would find his book by searching for that. Edit: Sorry if this came across as disrespectful. I don't think that a SEO hack in this case is bad. If you put your care and attention into writing and revising a 472-page textbook, you want people to find it. There's nothing wrong with that.
- quantumduck 4y ago
  I don't think Jeff cares about SEO. He was out probably looking for a simple domain and I'm sure algorithms.com, algorithms.org etc. were already taken. If I had to pick between say algorithms.me and algorithms.wtf, I'd definitely go with the second one, especially because students like me will remember it for life.
- jrumbut 4y ago
  In the linked page he refers to it as a more memorable link and presents it as an easy way to comply with the terms of this book's CC license. "Oh you're looking for an algorithms textbook, have you tried..."

johnohara 4y ago

Family, pancakes and algorithms. In that order (no pun intended).

primitivesuave 4y ago

Jeff Erickson was my favorite professor at UIUC, and his ability to explain complex ideas in meaningful ways inspired my own journey as a computer science educator.

pizza234 4y ago
He also has a very interesting history: > I have the lowest undergraduate GPA (2.4/4.0) of any professor I've ever met with reference to https://3dpancakes.typepad.com/ernie/2005/03/re_phd_with_low.html https://3dpancakes.typepad.com/ernie/2005/03/re_phd_with_low....
- dataflow 4y ago
  I love this quote: > I discovered (or remembered) that I was more interested in doing things RIGHT than doing them NOW, which is bad news in the software industry; this wasn't the place for me.

imadr 4y ago

The logo is "Khwarizmi" written in square kufic script, pretty cool

rg111 4y ago

Here are some books that I suggest to learn DSA properly: 1. A Common-Sense Guide to Data Structure and Algorithms from PragProg Bookshelf. Written in a very approachable manner with very good code. The best for self-learners. 2. Algorithms by Dasgupta, Papadimitriou, Vazirani (DPV). Very short and concise book- extremely well-written with a personality. Requires basic CS math. 3. Algorithm Design Manual by Skeina. Extremely approachable as well. Has 'battle stories' of algorithm usage. Good for self-learners. Links to problems in Leetcode is given. 4. CLRS is of course nice for a mathematically rigorous study.

marai2 4y ago
I'll second the recommendation above. For folks coming to algorithms for the first time I would recommend _Grokking Algorithms An illustrated guide for programmers and other curious people_ as a nice quick _tour_ of the field. And the _Common Sense Guide_ (mentioned above) as the next book. For complete beginners this book has the best simple explanations of algorithms I've read in any book (and I have a whole bunch of them).
trenchgun 4y ago
Why do you think Jeff Ericksons book is not hood for that?
- jefferickson 4y ago
  Well, I can tell you why I think my book is not good for that — it isn't designed to be that! My book grew out of lecture notes that I wrote for my algorithms classes at Illinois. My students are almost exclusively juniors and seniors. In particular, they already have several semesters of programming experience, a full semester of discrete math, and a full semester of data structures (which includes things like sorting and searching and the basics of algorithm analysis). They are the audience I wrote the book for. Equivalently, I have very little experience teaching those prerequisite classes, which makes me the wrong person to write a textbook about that more foundational material! At a more basic level: Different people are going to find different sources more or less useful. Different authors are better matches for different readers' backgrounds, intuition, and needs. My book ain't gonna work for everyone, because no single book works for everyone. I'm not familiar with Common Sense Guide — thanks for the suggestion! — but the other books listed above are all fantastic (for different reasons, and for different audiences).