Instagram Engineer Challenge solved with Javascript(feval.info)

Very neat. Makes me kind of embarrassed that I never got around to actually solving this challenge. I've had the web page open on my laptop since it first showed up on HN.

ronilan15 anni fa

Mine from the weekend here: http://ronilan.com/instagram-unshredder/

reledi15 anni fa

I preferred yours. You at least gave some comments about the solution.

ekosz15 anni fa

I wish I read the comments here first.

sktrdie15 anni fa

awesome! great job

coreyrecvlohe15 anni fa

Great job! Excellent coding style btw.

Mgccl15 anni fa

This challenge is the first real life program I wrote with Haskell.

https://github.com/Mgccl/mgccl-haskell/blob/master/random/un... (so it seems I don't like to specify the type of my functions...)

Explanation is here: http://chaoxuprime.com/2011/11/a-solution-to-Instagram-engin...

nandemo15 anni fa

Very nice.

Care for some unsolicited hlint-like suggestions?

Why not simply this:

    img <- readImage "file.png" 
    -- instead of this?
    t <- readImage "file.png"
    let img = t

Why not this:

    map (y!!) x  
    foldr ((:).(y!!)) []　x　-- instead of this?

Note that a way of reading fold g [] is that replaces the list constructor (:) (aka cons) with g. So (:) as argument of fold is probably not idiomatic, since foldr (:) [] is the same as id.

Mgccl15 anni fa

Thanks. hlint-like suggestions are always welcome.

I have no idea what was in my mind when I wrote

  foldr ((:).(y!!)) []　x

tikhonj15 anni fa

Heh, I did the same thing. It took me much too long to figure out that I needed to call ilInit...

ricardobeat15 anni fa

I (kind of) solved it with CoffeeScript but thought it wasn't a good idea to publish… if you do it's not a challenge anymore, is it?

https://github.com/ricardobeat/instagram-challenge

_gd3l15 anni fa

Nice work!

touchcream15 anni fa

I solved it in ocaml, I only had this development environment this week end but it was fun. I didn't posted it on my blog but if someone wants it, just ask ;)

carnevalem15 anni fa

You might also be interested in DARPA's similar challenge: http://www.shredderchallenge.com/

espes15 anni fa

Or for a similar, easier task, problem 3 "life" from this year's FARIO: http://orac.amt.edu.au/fario/11/problems_en.pdf

Here's case 8 to give you an idea: http://i.imgur.com/1fFzO.png :P

Test data here: http://dl.dropbox.com/u/76985/life-all-linux.zip

swang15 anni fa

So is this challenge over? I submitted an entry using Canvas as well but allowed users to drop image in from their desktop (only works in Chrome/Firefox though). Haven't heard from anyone at Instagram.

rjenkins15 anni fa

funny, that's exactly how mine works. Haven't heard anything either

rjenkins15 anni fa

Here's mine https://github.com/rjenkins/instagram-html5-unshredder

demo here http://memoization.com/unshred.html

asdfqwer123415 anni fa

so can someone actually explain how this works?

the-cakeboss15 anni fa

While I didn't look at how he did it, if I were to write something to do this, I would first locate each slice of the image. This could be accomplished using a rudimentary edge detection algorithm ( ie starting from the left, compare each column of pixels with the next, any large differences of course means an edge ). After that I might assign a weighted value to each edge of a slice, and then sort based upon those values.