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Ask HN: What's the hardest problem you've ever solved?

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Re: Ask HN: What's the hardest problem you've ever solved?

#261

Post by yholio »

yesenadam wrote: post #252
yholio wrote: post #90

I somehow decided I needed to cheat to pass a certain exam because I was basically crap at memorizing stuff. So I used an analogue wireless headphone, an induction loop around my neck and a mobile phone. Since I lacked an accomplice to dictate, I read aloud the hundreds of pages and recorded myself, careful to preserve and properly serialize things like complex formulas. This was before the era of iPods and SDCard pl…

You rejected ethical behaviour 'on principle', you even seem proud of that. Have you kept doing that in life? Do you feel like an impostor, presumably with your degree that you didn't think you could acquire without cheating, or couldn't be bothered? A surprising number of the replies to your comment also seem to think cheating like that at university is perfectly fine.

Ethics is not something that gets decided by the Dean and laid down in a code of academic ethics. The University is just a part of society and it has it's own perverse and quite unethical practices; for example, the tendency to grab one's money and time and not provide any substantial education in return. Furthermore, the university might be perfectly aware that it provides crap services and that fraud is rampant, yet enforce it's own rules selectively just to the point where fraud is hidden away and not damaging to it's reputation.

So while I agree with you in the abstract, I believe it's hard for people in the western system to relate and make moral judgements about the experiences of a student in post-communist Eastern Europe, where the rules were often gray. Fellow students were cheating on a grand scale, and up to that point, I had the same principled attitude towards cheating as yourself. Part of the reasons for creating "the system" was my revolt towards what I saw around me - the tacit acceptance that those with good cheating skills, which I lacked and did not develop early in my academic career, should be allowed to cheat their way to a degree, while I was supposed to memorize garbage.

Sure, my "rebellion" was unethical and compounded the social problem around me. But what could I realistically do, could I have changed anything? At least I saved me from myself, because otherwise I would have dropped-out. In the grand scheme of things, impeccable ethics is often a luxury and could have the exact opposite effect, letting only those with no ethics whatsoever to graduate.

Re: Ask HN: What's the hardest problem you've ever solved?

#262

Post by brianpgordon »

ph0rque wrote: post #102
beachy wrote: post #99

Earlier quoted context omitted.

IMO the most fun way to enter elevation data for your property would be to ride around on your farm bike with an altimeter lashed up to a smartphone, gathering data as you go.

Thanks for the idea! I found a variety of altimeter apps for the phone; I'll have to try just walking around my yard with one (or several), then see if it's possible to get elevation data on a map from such an app.

I'd suggest getting an app like Sensors Multitool for Android which gives you the raw output of your phone's sensors. I tried one of the altimeter apps a few years ago to see how tall a big hill was, and the value that the app reported turned out to be far off the actual value. There are various techniques for mixing and cleaning data from the GPS and barometric pressure sensors and a premade altimeter app (if it's not open source) obfuscates what's really going on with the values you'll actually end up seeing if you create an app for your microfarming project.

Also be aware that different phones have different levels of support for non-GPS location services. I was surprised to learn recently that my Pixel 3 can use data from the US, EU, and Russian satellite geolocation systems for better coverage/precision.

Re: Ask HN: What's the hardest problem you've ever solved?

#263

Post by brianpgordon »

BeefySwain wrote: post #73
thisacctforreal wrote: post #54

Editing a Minecraft save with sh and dd to resurrect my girlfriend's wolf.

Oh man, if Minecraft counts, I would say implementing a fully automated resource processing and storage system in FTB pre-Applied Energistics with Red Power and Buildcraft.

I made a PRNG with a 13-bit linear feedback shift register out of redstone with no mods. :D

Re: Ask HN: What's the hardest problem you've ever solved?

#264

Post by yetihehe »

seanmcdirmid wrote: post #96
jamestimmins wrote: post #83

Earlier quoted context omitted.

Ha, this is actually why I thought to ask it. Sadly, "I read the docs and wrote sample code for days until it became obvious" isn't what interviewers are looking for.

I know, but I debugged a lot of use cases, tried to narrow the scope of the bug, thought really hard about the execution in my head, and then fixed it all using an explicit semicolon.... Asking an experienced dev this question is like asking someone what was the hardest food they had to eat and how did they manage to swallow it. What is the interviewer hoping to learn by that?

It's a simple task to check that you really are experienced developer and not someone who stuffed his CV.

Re: Ask HN: What's the hardest problem you've ever solved?

#265

Post by yholio »

scottshapiro wrote: post #161
yholio wrote: post #90

I somehow decided I needed to cheat to pass a certain exam because I was basically crap at memorizing stuff. So I used an analogue wireless headphone, an induction loop around my neck and a mobile phone. Since I lacked an accomplice to dictate, I read aloud the hundreds of pages and recorded myself, careful to preserve and properly serialize things like complex formulas. This was before the era of iPods and SDCard pl…

How did the teacher not notice the headphones and question you about it during the exams?

The headphone was a very small analogue receiver that had it's own micro-battery, an inductor and amplifier - all about 4mm wide and 8mm long. You would place it deep inside the ear channel and it was invisible even to a person standing right next to you. The signal was induced by a coil you would wear around you neck and you would pipe raw audio into it.

Similar systems are even now on sale: https://www.olx.ro/oferta/sistem-de-copiat-casca-invizibila-...

Re: Ask HN: What's the hardest problem you've ever solved?

#266

Post by yesbabyyes »

zhte415 wrote: post #149
amp108 wrote: post #106

Earlier quoted context omitted.

One thing universities should teach is efficient problem solving. If it was more work to cheat than to memorize, I'd say you might want to re-evaluate whether "not memorizing things" is a principle you should cling so dogmatically to.

I had a programmable calculator during A Levels (UK sixth form college). Was talking Computer Science, Maths, Further Maths, a couple of others. These were not AS Levels, full A Levels. I also had the seemingly good idea it would be nice to program the calculator, initially just writing algorithms like bubble-sort for CS that could be referred to, then extending to Statistics showing working for various statistical m…

I wrote a raster graphics editor for my Casio programmable graphing calculator. I also wrote it exclusively on the calculator. Did it to one-up my class mate, who had done one previously--mine had better features (no dot in the center of circles, could also do ellipses, had a spray function), and it was half the LOC.

Casio BASIC had subroutines in IIRC 36 registers ([A-Z0-9], conditional jumps and labels.

I wish I had that source code. I can't see how I would ever do something like it again.

Re: Ask HN: What's the hardest problem you've ever solved?

#267

Post by brianpgordon »

navinsylvester wrote: post #205

This was 15 years ago. I signed up to a correspondence course to study company law after my under graduation(not CS). Was bored so wanted to pick a hobby and was fascinated by robotics/automation. Self thought 8051 by reading Kenneth J. Ajala and this hobby soon turned lucrative. I signed up with an institute which was helping college students with their final year projects. I had a college junior(Amazing guy who is…

> Even before i could start writing a single line of code the CTO left the company after a spat and without proper hand-off. I wouldn't wish this scenario even upon my worst enemy.

I know that feel. My first full-time job right out of college, the lead developer left only a week after I joined. I individually inherited a 70k+ SLOC project (in Java, but still...) of his that sorta kinda worked, in a domain I had no experience in. Especially as a new grad there was a massive amount of anxiety trying to get up to speed with nobody to ask questions to. But as the months went by I learned every nook and cranny of every class in the codebase, and was able to make big sweeping changes. It turned out to be an incredibly valuable lesson in soldiering on and not getting intimidated.

Re: Ask HN: What's the hardest problem you've ever solved?

#268

Post by choicenotchance »

matheist wrote: post #79

Probably not hardest, but one that sticks in my mind was that I downloaded an old copy of Jedi Knight II onto my computer and was excited to play it again... but it crashed on launch. Or rather it would throw a modal dialog (complaining about graphics something-or-other) and go into a loop of system beeps. So I attached to it with gdb... and started going down a rabbit hole of stack traces and assembly code. I don't…

Yeah, that happened

Re: Ask HN: What's the hardest problem you've ever solved?

#269

Post by ransom1538 »

My task: Take a top 500 website, all written in smalltalk (no documentation), and port it to a modern scripting language. The company has: no money, a hostile customer base, angry previous engineers, angry management, and hostile current employees. The site generated billions of webviews and was all unstructured (no database) user generated content.

It was grueling. There was only one smalltalk engineer that would talk to us (the others quit, or weren't paid). Getting the dev environment running was impossible due to license issues with cincom. Luckly, I was able to get 3 smalltalk endpoints that would dump XML -- using the last remaining favors we had with the last small talk dev. Using this and layers of hacks we were able to start porting in 6 months.

The site was sold (3?) times and was ported again to something else.

Re: Ask HN: What's the hardest problem you've ever solved?

#270

Post by aerovistae »

herodotus wrote: post #197

When I was a CS prof, many, many years ago, our undergraduate lab had Macs with floppy disks. I asked the University to pay for installing 10MB Hard Drives in the Macs. I was asked to present my case to the deans council. At the meeting, I said that the students used the floppy to load their development environment. I said that, with a hard drive, it took 10 secs to load and be ready. With the floppy, I said it took…

I've used this trick many times when people underestimate how long a few minutes can be in certain contexts. It works astonishingly well. Happy to see I'm not the only one!
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