C#•2y ago

✅ Regex pattern to match unique words each with 3 unique characters

Given a multiline input text:

abc
aaaa
bcde
acd
abc
abc
xyz

abc
aaaa
bcde
acd
abc
abc
xyz

abc
aaaa
bcde
acd
abc
abc
xyz

abc
aaaa
bcde
acd
abc
abc
xyz

I am looking for a regex pattern that matches unique words each consists of exactly 3 unique characters.
The expected output:

acd
xyz

acd
xyz

acd
xyz

acd
xyz

Edit:
For new visitors, this question can actually be solved with

negative lookbehind

negative lookbehind

negative lookbehind

negative lookbehind and

negative lookahead

negative lookahead

negative lookahead

negative lookahead.
If you are in hurry, you can jump to https://discord.com/channels/143867839282020352/1204500978741673994/1204519081663926304
and return again to this message ✅ Regex pattern to match unique words each with 3 unique characters in the future.
I may update with the solution.

Jimmacle•2/6/24, 6:58 PM

what have you tried?

cap5lut•2/6/24, 7:11 PM

thats something u shouldnt do with regex

cap5lut•2/6/24, 7:12 PM

?! i said do not use regex for this

cap5lut•2/6/24, 7:15 PM

u know the closest regex pattern string to validate an email address is ~4k characters long and is still not completely correct.
there are problems where regex fits and some where they dont

Jimmacle•2/6/24, 7:16 PM

my suggestion is also not to use regex for this

Jimmacle•2/6/24, 7:17 PM

use the right tool for the problem

cap5lut•2/6/24, 7:17 PM

as far as i know its simply not expressable as regex what u r trying to do

Jimmacle•2/6/24, 7:18 PM

way simpler to put the lines in a hashset first then remove entries with duplicate characters (or the other way around)

cap5lut•2/6/24, 7:18 PM

unless u want to

or

or

all possible combinations

Jimmacle•2/6/24, 7:20 PM

did an interviewer ask this question?

Jimmacle•2/6/24, 7:20 PM

i'd give them the same answer, regex isn't the right tool

cap5lut•2/6/24, 7:21 PM

u know if u would have a format like abdasdc-123-xy2434zabdasdc-123-xy2434z and the requirements to have these unique chars per segment u would write a regex to find the segments and post process them with code

Original message was deleted

cap5lut•2/6/24, 7:21 PM

unless they expect the answer "u dont do it with a regex"

cap5lut•2/6/24, 7:22 PM

even if there is one i dont know of, it would be such a complex thing that its by far less performant than writing it in code urself

Jimmacle•2/6/24, 7:22 PM

a business shouldn't care if you can write a complicated regex to solve a contrived problem, they should care that you can solve the problem using any tool at your disposal

Jimmacle•2/6/24, 7:23 PM

it's like asking a carpenter to build a chair with nothing but an angle grinder

Jimmacle•2/6/24, 7:24 PM

for an interview or for what?

cap5lut•2/6/24, 7:24 PM

yeah, but they wouldnt use problems to solve that aint solvable with regex

cap5lut•2/6/24, 7:26 PM

if u want to look at "advanced" regex stuff thats something like back referencing or recursion

Jimmacle•2/6/24, 7:27 PM

can we clarify something

Jimmacle•2/6/24, 7:27 PM

is this actually a question you expect to get, or is this something you made up without knowing if it's solvable or not?

cap5lut•2/6/24, 7:27 PM

regex is pattern matching, what u want to do is semantics, thats nothing regex is used for

Only in .NET stacks do we trustOP•2/6/24, 7:28 PM

I don't know it is solvable or not with regex.

Jimmacle•2/6/24, 7:28 PM

so maybe don't insist on getting a regex solution

Original message was deleted

cap5lut•2/6/24, 7:28 PM

ever tried to play number guessing with it? dont trust that damn thing

OOnly in .NET stacks do we trust I don't know it is solvable or not with regex.

cap5lut•2/6/24, 7:29 PM

i really did a lot with regex, but this seems impossible unless u r

or

or

ing all possible combinations, and have fun doing that with unicode

Jimmacle•2/6/24, 7:32 PM

it would be easier to help if you asked about actual practice questions for your test

cap5lut•2/6/24, 7:33 PM

feels to me like that they created this problem for themselve to figure out how to solve it

Jimmacle•2/6/24, 7:33 PM

well, asking chatgpt definitely isn't the right way then :KEKW:

cap5lut•2/6/24, 7:34 PM

who knows what it spits out, maybe its some garbage that can lead ur thoughts to something useful

cap5lut•2/6/24, 7:34 PM

but in 99% of the time it doesnt

cap5lut•2/6/24, 7:35 PM

either my network wiped or discord is slow, i meant to type 99%

cap5lut•2/6/24, 7:36 PM

ah now its updated

cap5lut•2/6/24, 7:38 PM

reminds me of an old job, there they had a pattern to name their files but over the years it changed, but they didnt rename the old ones

cap5lut•2/6/24, 7:39 PM

so the thoughtfully built regex wasnt enough to determine all the info from the filenames and then it was bruteforcing on the database entries

cap5lut•2/6/24, 7:41 PM

in the end it was still impossible to differentiate between some entries and the pathologists had to check the medical data to see what fits together
(it was anonymized data for a research project)

Jimmacle•2/6/24, 8:11 PM

@talk is cheap, show me the code i really don't want to keep bringing this up, please stop deleting messages

Jimmacle•2/6/24, 8:11 PM

it makes it impossible to read the thread after the fact

Jimmacle•2/6/24, 8:14 PM

this server isn't just for you to ask questions then delete the conversation because you got your answer, it's a place for everyone to learn from all the questions being asked

Jimmacle•2/6/24, 8:14 PM

that's not what i'm asking you to do

Jimmacle•2/6/24, 8:14 PM

i'm asking you to stop deleting messages

Jimmacle•2/6/24, 8:15 PM

can you do that?

Original message was deleted

MODiX•2/6/24, 8:16 PM

https://cdn.discordapp.com/attachments/569261465463160900/826859856719380500/1niu5wN.png

Jimmacle•2/6/24, 8:17 PM

cool, my time is too valuable to be wasted by your constantly poor behavior and i won't be putting any more effort into helping you

Jimmacle•2/6/24, 8:17 PM

can't say i didn't try

cap5lut•2/6/24, 8:31 PM

oh wow they really deleted everything

cap5lut•2/6/24, 8:34 PM

in case u r reading this: what u asked for wasnt anything to be ashamed of if u felt that way
everyone asks "stupid" questions, not because they are stupid but because they dont YET have the knowledge

cap5lut•2/6/24, 8:53 PM

@talk is cheap, show me the code may i ask why u delete messages? u can dm me and i wont publicate them, i just want to understand

cap5lut•2/6/24, 8:53 PM

(by "them" i mean ur messages)

cap5lut•2/6/24, 8:57 PM

i take that as a "no"

✅ Regex pattern to match unique words each with 3 unique characters

Similar Threads

Similar Threads

Similar Threads