rak1507‭

Challenge Given an array of numbers return the cumulative count of each item. This is the number of times an item has occurred so far. Examples [1,1,2,2,2,1,1,1,3,3] -> [1,2,1,2,3,3,4,5,1,2]...

19 answers  ·  posted 3y ago by rak1507‭  ·  last activity 1y ago by WheatWizard‭

Challenge Given two strings a and b, return the shortest string s so that s starts with a and ends with b. (Inspired by https://chat.stackexchange.com/transcript/message/57816868#57816868 ) Exam...

8 answers  ·  posted 3y ago by rak1507‭  ·  last activity 3y ago by radarek‭

Challenge Given an array consisting of positive integers and 0s, return it with 0s acting like backspaces. Leading backspaces do nothing, and more backspaces than elements also does nothing. Cre...

6 answers  ·  posted 3y ago by rak1507‭  ·  last activity 3y ago by Shaggy‭

Description APL trains are a series of functions, that get applied to an argument in this way: (f g) x = f g x (f g h) x = (f x) g (h x) (a b c d e f) x = (a (b c (d e f))) x = a (b x) c (d x) ...

7 answers  ·  posted 3y ago by rak1507‭  ·  last activity 3y ago by Shaggy‭

Credit This challenge is taken with permission from https://www.mysterytwisterc3.org/en/challenges/level-1/beaver-code Description The encryption method is as follows: The plaintext is divided ...

6 answers  ·  posted 3y ago by rak1507‭  ·  last activity 3y ago by Shaggy‭

Jelly, 7 bytes *Ḃ×½ḞµƬ *Ḃ×½ḞµƬ *Ḃ input ^ (input % 2) ×½ multiply sqrt(input) Ḟ floor µƬ iterate until converged and collect results Try it online!

posted 3y ago by rak1507‭

APL (Dyalog Extended), 1 byte ⍸ ¯\(ツ)/¯ Try it online!

posted 4y ago by rak1507‭

Note: This challenge was underspecified and bad, and as such I would not encourage answering it in the future. Challenge You will be given a single 2D boolean array $M$. You may take its dimensi...

1 answer  ·  posted 4y ago by rak1507‭  ·  edited 3y ago by rak1507‭

Definition $F_{n}\left(0\right)=0$ $F_{n}\left(1\right)=1$ $F_{n}\left(x\right)=n\cdot F_{n}\left(x-1\right)+F_{n}\left(x-2\right)$ For example: $F_{1}=\left[0,1,1,2,3,5,8,13,21,34,55,89...\ri...

3 answers  ·  posted 3y ago by rak1507‭  ·  edited 3y ago by General Sebast1an‭

Solutions by ngn https://chat.stackexchange.com/transcript/message/57690032#57690032 APL 17: {⍵[⍋⍋⍉⊖2⊥⍣¯1⍳≢⍵]} ngn/k 13: {x@<<+|2\!#x} These are too good not to post.

posted 3y ago by rak1507‭  ·  edited 3y ago by rak1507‭

APL (Dyalog Classic), 47 bytes i←+∘1⋄d←-∘1⋄s←×⍨⋄o←⎕∘←⋄{}{0⌈a×256≠a←⍎⍕⍺,⍵}/⌽0,⍞ Try it online!

posted 4y ago by rak1507‭