CMC: Given a list of integer lists, [[a1, a2, a3, ...], [b1, b2, b3, ...], [c1, c2, c3, ...], ...], check whether a1=a2=a3=...≡a & b1=b2=b3=...≡b & c1=c2=c3=...≡c & ... and a≠b≠c≠...

[[2, 2, 2], [3, 3, 3, 3, 3], [4, 4, 4]] -> True; [[2, 2, 1], [3, 3, 3, 3, 3], [1, 1, 1]] -> False; [[1,1,1],[3,3,3,3],[1,1,1,1,1]] -> False

(By a≠b≠c≠... I mean all letters are different not only a≠b and b≠c, but rather a≠b, b≠c and c≠a).

@Mr.Xcoder Does a, b and c etc refer to the repeated value, not the list as a whole?

a, b and c refer to the repeated values.

CMC': Given a predicate 𝓟(x) (which you can assume is the above link if you want) and a list X = {x1, x2, x3, ..., xn}, reproduce the behaviour of a group-by function applied to X with 𝓟(x).

@Mr.Xcoder 9 bytes. EAA567D03F26E147BC8BA137C04DEB8C

@Mr.Xcoder 4 bytes. FE10A73514BE9054D4DF0859470BD1E9

@cairdcoinheringaahing O_o

@Mr.Xcoder What's your bytecount?

I did not write a solution to any of them yet.

@Mr.Xcoder Test case: ṛ/, [[1,2,3],[1,2,2],[1,1,1],[1,2,2,3,2],[3,3,3]] -> [[[1,2,3],[3,3,3]],[[1,2,2],[1,2,2,3,2]],[[1,1,1]]]

@cairdcoinheringaahing Passes ^, right?

I had a 4-byte solution in my which failed this test case, so I'm just checking

@Mr.Xcoder Yes, mine passes that test case

Sorry for the late reply

I'd enjoy a spoiler, if you don't mind :)

@Mr.Xcoder Here you go :P

My attempts have gone totally wrong I guess, most are over 10 bytes.

Thanks

Not fully sure why it works but ¯\_(ツ)_/¯

... O... k...?

Brb, trying to understand how that works.

@Mr.Xcoder Spoiler for 9 bytes