Classic Algorithms Implemented in JavaScript • Hacker News Board

Re: Classic Algorithms Implemented in JavaScript

#31

Post by uncletaco » Fri, Jul 20, 2018, 8:58 PM UTC

austincheney wrote: post #28

uncletaco wrote: post #18

Earlier quoted context omitted.

the keywords "ill" and "duh" will cause collision. I know this because I ran into this issue trying to be clever on leetcode's anagram grouping problem.

Using what hash mechanism? I tested with SHA512 and got different results: * ill - 2ae60a99f87408af77066079879865d907201ff44e7b1f26d911afcd1097c4c32162b97546c404d3a305396698ea530d3c3690adb7dcbc91ec685837f895a37b * duh - e44e6d93cd165ec8cdeaa632abe1c35d9a71533cc68072e100c5307ea3be17bc4f10e258785bef77d31664be0f1c3f427528c7450d52082a90c4ee86c7012184

What jovial said. Adding ascii yields the same integer for ill and duh.

Re: Classic Algorithms Implemented in JavaScript

#32

Post by devmunchies » Fri, Jul 20, 2018, 9:27 PM UTC

its pretty interesting to see the steep curve for how many stars this repo has collected in such a short amount of time

http://www.timqian.com/star-history/#trekhleb/javascript-alg...

Re: Classic Algorithms Implemented in JavaScript

#33

Post by cachesking » Fri, Jul 20, 2018, 9:52 PM UTC

acqq wrote: post #8

cachesking wrote: post #4

It would be cool if these had tests around them where it made sense.

Already there: https://github.com/trekhleb/javascript-algorithms/blob/maste...

Beautiful. Apparently, I was not paying attention.

Re: Classic Algorithms Implemented in JavaScript

#34

Post by hackandtrip » Fri, Jul 20, 2018, 9:57 PM UTC

k__ wrote: post #20

uncletaco wrote: post #19

Earlier quoted context omitted.

Well its not a list per se but many of the interview prep sites tag their problems with the appropriate algorithm/data structure for the job. As someone who has his first SV phone technical interview on Monday and has done ~30 problems in the last two weeks, I can say after solving about 2-3 of them over a number of hours or days you start to recognize which algorithm will get the job done from the problem descriptio…

Interesting :D Would be nice if you could post a list of your resources :)

Not OP, but a resource commonly suggested is "Cracking the Coding interview"

Re: Classic Algorithms Implemented in JavaScript

#35

Post by blt » Sat, Jul 21, 2018, 4:18 AM UTC

Great resource, but I couldn't help laughing at the plot with asymptotic complexity classes categorized as "horrible, bad, fair, good, excellent", as if it's independent of the problem.

Re: Classic Algorithms Implemented in JavaScript

#36

Post by paidleaf » Mon, Jul 23, 2018, 3:40 PM UTC

cabalamat wrote: post #16

The implementation of a hash table uses a hash table, which feels like cheating to me. Also I suspect that adding together the ascii values of the characters in the key is not necessarily the best hash function.

> Also I suspect that adding together the ascii values of the characters in the key is not necessarily the best hash function.

Still better than using the length of the string as your hash value. Not my proudest moment but sometimes, you want to see the world burn. That and I forgot to do my hw and class was in a few minutes.