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Algorithms, by Jeff Erickson

jeffe.cs.illinois.edu

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Re: Algorithms, by Jeff Erickson

#231

Post by konart »

mden wrote: post #101
fwip wrote: post #90

Earlier quoted context omitted.

I would agree that words like "obvious" or "trivial" can be disheartening to a learner. If it's obvious to the reader, they know it whether or not you tell them it's obvious. If it's not obvious to them, then they will try to figure it out. Telling this person "it's obvious" only serves to make them feel bad about not getting it right away.

I felt that way when studying math in college, but after sometime I actually came to like the use of "clearly" and the like as it can be used as a check on whether you've spent enough time internalizing the previous information. It's one thing to have a text or a person hold your hand through algorithms or theorems, it's another to be able to do it yourself. So getting hit with a "clearly" that feels unjustified is o…

Sometimes this is th'e case, yes, sometimes it is not.

An example: http://jeffe.cs.illinois.edu/teaching/algorithms/book/Algori... Page 15

> It’s quite easy to show that the singing time is Θ(n2); in particular,the singer mentions the name of a gift ∑ni=1i=n(n+1)/2times (counting thepartridge in the pear tree).

I'm pretty sure that I still remember how to read the formula and I even know what does Θ(n2) means, but it's still unclear for me how do we get n^2 and this formula from the "NDaysOfChristmas(gifts[2..n]):" example.

Re: Algorithms, by Jeff Erickson

#233

Post by emme »

ff_ wrote: post #213
emme wrote: post #211

Earlier quoted context omitted.

We designed a small tool to bring the fairy metaphor even to lower secondary school students. I actually believe it is a very promising approach. "Nothing to fear but fear itself: introducing recursion in lower secondary schools" https://aladdin.di.unimi.it/materiali/pubb/2017_latice.pdf

Super interesting! Do you happen to have an Italian translation/version of the paper?

Just remembered: in fact the work was a master thesis, and the final report is in Italian. http://aladdinsrv.di.unimi.it/archive/pdf/tesi-previtali.pdf

Enjoy!

Re: Algorithms, by Jeff Erickson

#234

Post by andrewflnr »

solveit wrote: post #179
nichochar wrote: post #170

Earlier quoted context omitted.

I think you're running under the assumption that all students making the request are doing it for the right reasons. I could be wrong, but my intuition goes the other way and I'm assuming most students do it to get a better grade, not learn more.

Yeah no, you don't get to say students should care more about learning than grades when jobs, opportunities, and scholarships given by the very university that claims learning is more important are riding on grades. It is the professor's responsibility to grade accurately, and honestly if there is so much inconsistency in grading that there's a significant probability that the student will lose marks despite having p…

As long as we're getting all realpolitik about it, the reason is that lots of students are assholes who will run roughshod over any professor who shows weakness. Source: was a student, watched it happen routinely.

Meanwhile, in a less politically charged situation, it's pretty normal, or at least smart, to go back over any area where you messed up with a fine-toothed comb.

If, and this is a rather pessimistic assumption, if the student is likely to lower their grade on a re-test, in my experience it's more likely to be because the original grader was being generous in the face of ambiguity, rather than systemic random errors. That's because the graders are mostly nice people. If that's not good enough for someone, they damn well better have a good reason for it. I have no problem with policy that enforces this. The politics are a distraction from the ethical question.

Re: Algorithms, by Jeff Erickson

#235

Post by andrewflnr »

jefferickson wrote: post #86
_underflow_ wrote: post #3

> Please do not ask me for solutions to the exercises. Even if you are [an] instructor, I will say no. That's kind of a bummer. I like to be able to check my answers when teaching myself things. Am I somehow alone in that?

Hi, I'm the author. I'm honestly seriously torn about this. There is a serious tension between pedagogical needs of students in formal classrooms and the pedagogical needs of self-learners. I've chosen to aim for the former. Yes, I know it's a bummer. (From experience) providing solutions interferes with the learning process of my own students at Illinois. I have to change up homeworks and exam questions every semest…

I find this approach bizarre and honestly kind of backwards. My favorite math professor assigned homework but essentially (sometimes literally) didn't grade it at all. It was strictly for our own learning. I did it on scratch paper and threw it away, but enjoyed it more because I didn't have to worry about formatting it for clarity. The exams constituted almost all of our grade, and were plenty to convince at least me to take the exercises seriously. I've often wished every mathish course was taught this way. You don't have any choice but to change the exams every time (or people will cheat), and exercises are entirely designed to help us learn, so why not lean into it?

Re: Algorithms, by Jeff Erickson

#236

Post by ibash »

ausjke wrote: post #73

After a quick browser it seems a little too academic for daily programmers like myself. Would love to learn more about practical dynamic programming these days, hope there is a book about that extensively.

Go back and read it - it’s not!

Re: Algorithms, by Jeff Erickson

#237

Post by webmaven »

atombender wrote: post #227
jefferickson wrote: post #204

Earlier quoted context omitted.

You can get an EPUB and MOBI versions from the Internet Archive (auto-converted from my uploaded pdf), but I can't vouch for its quality. All the fonts are baked into the PDF, so it should be readable anywhere; if it isn't, please submit a bug report! But if you're looking for a format that lets you reflow the text, by changing the margins or font or text size, you're out of luck. The only way to write something like…

I don't know what you use to typeset the book, as I can't find any source files, but isn't LaTeX really good at this? I'm not sure what makes it hard to reflow. The text seems to be mostly paragraphs with figures, inline formulas and footnotes; pretty basic stuff, no? (O'Reilly's books were famously typeset with Troff/Groff for many years, though I don't know how painful that was or how advanced their typesetting nee…

> (O'Reilly's books were famously typeset with Troff/Groff for many years, though I don't know how painful that was or how advanced their typesetting needs were.)

I beleive that O'Reilly Media has used ASCIIDoc[0] as their preferred internal format for quite a few years. Formulas are supported through ASCIIMthML[1].

More recently, they seem to have transitioned to HTMLBook[2] as a preferred source format for systems like Atlas[3].

[0] ASCIIDoc is basically a Markdown-like (or ReStructuredText-like) format that is feature-equivalent to DocBook XML: http://asciidoc.org/

[1] http://asciidoc.org/asciimathml.html

[2] http://oreillymedia.github.io/HTMLBook/

[3] https://atlas.oreilly.com/

Re: Algorithms, by Jeff Erickson

#239

Post by webmaven »

jefferickson wrote: post #204
webmaven wrote: post #35

Great resource, though I wish it was available as an EPUB (or MOBI, or AZW3).

You can get an EPUB and MOBI versions from the Internet Archive (auto-converted from my uploaded pdf), but I can't vouch for its quality. All the fonts are baked into the PDF, so it should be readable anywhere; if it isn't, please submit a bug report! But if you're looking for a format that lets you reflow the text, by changing the margins or font or text size, you're out of luck. The only way to write something like…

> I can't vouch for its quality

The quality of the EPUB is terrible, it looks like it was OCR'd from images of the pages, not just converted from PDF.

Can you make the source format for the book available?

Re: Algorithms, by Jeff Erickson

#240

Post by kirkules »

skizm wrote: post #219

What the heck is the trivial one liner to check who will win a chess game given both players play perfect?

I suppose the claim of the existence of this one liner might be the same as the claim that one of the players can always force a win, in which the line is something like "return 'white'" or "return 'draw'"
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