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I Got a Knuth Check for 0x$3.00

nickdrozd.github.io

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31–40 of 149 posts

Re: I Got a Knuth Check for 0x$3.00

#31

Post by Rapzid »

thaumasiotes wrote: post #25
jaredsohn wrote: post #16

Does the algorithm described for finding a number in an unsorted array using minimal checks really work? Probably is addressed more in the book but didn't see my concerns in the post. The algorithm I am referring to is: " 1. Check if the current item is the desired one. If it is, return success if the pointer is within the array bound and return failure if it isn’t; otherwise 2. Increment the pointer and continue. "…

> Does the algorithm described for finding a number in an unsorted array using minimal checks really work? Probably is addressed more in the book but didn't see my concerns in the post. > I think it assumes that all values will be found in memory somewhere That assumption is not made; the post does cover this. You left out the beginning of the algorithm: > A more clever search algorithm can do it with just one bound…

I think a more typical, high performance operation for copying arrays would be using mem copy operations. This is how Go handles a lot of slice operations under the covers.

If it's a C style array you could always just keep it one larger than the actual size; perhaps place a null value at the end and swap it out as needed. Just build an abstraction over it.

Re: I Got a Knuth Check for 0x$3.00

#34

Post by weinzierl »

dmix wrote: post #15

https://www-cs-faculty.stanford.edu/~knuth/boss.html Someone found and submitted 700+ errors. I wonder where he finds the time to send all of these out! I guess it’s like an open source project getting PRs.

Maybe he just likes working through text books thoroughly?

I personally find it quite valuable to compile a list of "outstanding questions" for the text books I read. Usually most of my questions are resolved before I finish the book. The ones that remain, often turn out to be simply errors. Finding the the errors is just a by-product of the learning process for me.

Re: I Got a Knuth Check for 0x$3.00

#35

Post by wodenokoto »

hackermailman wrote: post #24

Any published authors here? I once went through a cheaper international edition of a large computer science text, and built a massive errata of all the mistakes (primarily found in the exercises) then submitted it to the authors who basically told me 'Thanks but we don't give a shit about that version, only the US edition'. Any reason there would be that many mistakes in the international version? Does Pearson publis…

I’m sorry you got such a shitty reply to what must have been a lot of hard work.

Did you try to contact the Malaysian professors?

Regardless, thank you for the warning about international editions.

Re: I Got a Knuth Check for 0x$3.00

#37

Post by svat »

dmix wrote: post #15

https://www-cs-faculty.stanford.edu/~knuth/boss.html Someone found and submitted 700+ errors. I wonder where he finds the time to send all of these out! I guess it’s like an open source project getting PRs.

Knuth gives higher rewards for works he believes have fewer errors. For TeX and METAFONT, he started with 1 cent for every bug found, and doubled it each year until reaching the current value of 327.68 dollars (= 0x$80.00): for example Eberhard Mattes and Oleg Bulatov (joint 7th on the list) have all their amount from a single (and the latest so far) bug found in TeX and METAFONT each (if you're wondering what the bugs were: https://tex.stackexchange.com/questions/154873/ — the TeX bug was a missing space in the debug output for a macro with an empty name).

Incidentally, he seems to have had this policy of giving out rewards for errors from the time he was a college student: http://ed-thelen.org/comp-hist/B5000-AlgolRWaychoff.html#7

Re: I Got a Knuth Check for 0x$3.00

#38

Post by edge17 »

hackermailman wrote: post #24

Any published authors here? I once went through a cheaper international edition of a large computer science text, and built a massive errata of all the mistakes (primarily found in the exercises) then submitted it to the authors who basically told me 'Thanks but we don't give a shit about that version, only the US edition'. Any reason there would be that many mistakes in the international version? Does Pearson publis…

International Editions differ often in the problems at the ends of the chapters in order to protect US and other western markets. Differences in the problems means it discourages students from buying things that may lead to incorrect answers to assigned problem sets.

As for things just being flat out wrong, I can only imagine this discourages US/western students from buying International Editions to save money.

Re: I Got a Knuth Check for 0x$3.00

#40

Post by dchest »

Someone wrote: post #9

”In 1960, Karatsuba attended a seminar wherein Kolmogorov pitched his n2 conjecture. 3) “Exactly within a week” Karatsuba devised his divide-and-conquer algorithm. […] Thus the error is that 1962 should be 1960.” Based on the information given, the correct year _could_ be 1961, too. When, exactly, was that seminar? Were Soviet universities at the time closed over Christmas?

> Were Soviet universities at the time closed over Christmas

No, Christmas was not an official holiday. Also, it's on the 7th of January.

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