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Elevator Saga: An elevator programming game (2015)

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Re: Elevator Saga: An elevator programming game (2015)

#61

Post by [deleted] »

alasdair_ wrote: post #12
adenozine wrote: post #3

I used to interview programmers with an elevator programming problem. Neat to see it expanded so excellently and cleanly in this piece. Well done!

I had this question during a Google interview. The interviewer became annoyed when I suggested that an elevator that sometimes went backwards to pick ip someone on a just-missed floor could at least be interesting, if not perfectly efficient. They had a preconceived idea that they wanted a stateless system and didn’t like my stateful approach, even if it was potentially better for end users.

[deleted]

Re: Elevator Saga: An elevator programming game (2015)

#62

Post by aidenn0 »

MobileVet wrote: post #39
Jun8 wrote: post #15

Made me remember an interesting anecdote: During my PhD at Purdue I had the good luck to take the Pattern Recognition (nowadays would be called ML) course from Prof. Fukunaga, one of the pioneers in the field ( https://en.m.wikipedia.org/wiki/Keinosuke_Fukunaga ). In one of his classes he mentioned that years ago a company came to him, requesting his expertise in optimizing movement of a bank of elevators. He thought…

Boiler Up! I had Prof Fukunaga for EE301 I think (Might have been EE202). I was too young and dumb to recognize his brilliance.

I started in physics before switching to CS. I'm glad the ECE department is good, because the CS department was terrible.

Re: Elevator Saga: An elevator programming game (2015)

#63

Post by webmaven »

curmudgeon22 wrote: post #27

During Covid, I've often wished I could reprogram the elevator of the apartment building I live in. The current rule is only 2 people can be in the elevator at a time. Problems that arise: * Elevator stopping frequently, but already at capacity, slowing down overall performance * Elevator always goes to bottom (or top) first to pick up passengers going up (or down). This means if your waiting on the ground floor and…

> Ability to set elevator as "full". Even if abused by a single person, still better than multiple wasted stops.

I'd add a couple of sensors (one for volume and one for weight) to let the elevator itself determine how full it is and act accordingly.

I would also still have a "full" button for people to press, but not have the button actually do anything, except maybe light up.

Re: Elevator Saga: An elevator programming game (2015)

#64

Post by Thorrez »

bombcar wrote: post #19
alasdair_ wrote: post #12

Earlier quoted context omitted.

I had this question during a Google interview. The interviewer became annoyed when I suggested that an elevator that sometimes went backwards to pick ip someone on a just-missed floor could at least be interesting, if not perfectly efficient. They had a preconceived idea that they wanted a stateless system and didn’t like my stateful approach, even if it was potentially better for end users.

That’s an example of a thing that may work well but would piss users off - it apparently reversing would annoy.

Not just annoy. Some users might think they accidentally got on the wrong elevator ("oops, I got on a down elevator instead of an up elevator") and leave the elevator at the next floor to ask for a new elevator.

Re: Elevator Saga: An elevator programming game (2015)

#65

Post by GreenWatermelon »

Daneel_ wrote: post #60

Call me weird, but I’ve been fascinated by elevator logic since I was a child. I had a math curiosities book that dedicated a chapter to it and after reading that I was hooked on knowing more. I wish my knowledge of JavaScript was more than “programming language that’s not Java” so I could actually play this. Could anyone recommend an online introduction to JS so I can attempt to play this? I’m more of a bash guy.

If you know your way around any programming language, then hop on (https://learnxinyminutes.com) to quickly get the hang of any other language.

Re: Elevator Saga: An elevator programming game (2015)

#66

Post by grensley »

adenozine wrote: post #3

I used to interview programmers with an elevator programming problem. Neat to see it expanded so excellently and cleanly in this piece. Well done!

I really like just asking "how do elevators work"?

It's so open ended and they can talk about anything from the algorithm, to the mechanical design of elevators, to the UI, to a high-level discussion of all the different components.

Really lets you know quickly which parts of systems candidates are interested in.

Re: Elevator Saga: An elevator programming game (2015)

#67

Post by nextlevelwizard »

ziptron wrote: post #29

I always wished elevator buttons could toggle. If you accidentally press the wrong floor, just press it again to cancel. This may not work in all situations, but in some situations, it could be a time saver.

the thing is that elevators are these days way more complex than anybody would even imagine, but the thing also is that there are no tutorials given to people who use them. Also extra features cost extra money and building owners usually just want the very basic stuff for residentals.

Re: Elevator Saga: An elevator programming game (2015)

#68

Post by joshka »

curmudgeon22 wrote: post #27

During Covid, I've often wished I could reprogram the elevator of the apartment building I live in. The current rule is only 2 people can be in the elevator at a time. Problems that arise: * Elevator stopping frequently, but already at capacity, slowing down overall performance * Elevator always goes to bottom (or top) first to pick up passengers going up (or down). This means if your waiting on the ground floor and…

Would a first order approximation of "full" be "has two destinations"

Re: Elevator Saga: An elevator programming game (2015)

#69

Post by nextlevelwizard »

curmudgeon22 wrote: post #27

During Covid, I've often wished I could reprogram the elevator of the apartment building I live in. The current rule is only 2 people can be in the elevator at a time. Problems that arise: * Elevator stopping frequently, but already at capacity, slowing down overall performance * Elevator always goes to bottom (or top) first to pick up passengers going up (or down). This means if your waiting on the ground floor and…

I mean you aren't wrong, but also this is all logic tha has existed in elevators for decades, but if your building owner just slaps a piece of paper artificially creating a limit the elevator system won't be aware of it. On other hand they could have made an configuration order and paid to change the behavior of the elevator, to reduce its capacity. Then it wouldn't make extra stops since it would know that it is at max capacity.

Re: Elevator Saga: An elevator programming game (2015)

#70

Post by nextlevelwizard »

joshka wrote: post #68
curmudgeon22 wrote: post #27

During Covid, I've often wished I could reprogram the elevator of the apartment building I live in. The current rule is only 2 people can be in the elevator at a time. Problems that arise: * Elevator stopping frequently, but already at capacity, slowing down overall performance * Elevator always goes to bottom (or top) first to pick up passengers going up (or down). This means if your waiting on the ground floor and…

Would a first order approximation of "full" be "has two destinations"

You could but if passengers knew that it would result into single passengers pressing two car calls so they could get private elevator ride. Rather you would just use the normal passenger counting system i.e. correlating weight scale with photocell cuts.
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