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Challenges

Comments on Make my number a set

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Make my number a set

+7
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Natural to set

(set meaning an unordered collection with no duplicates, though answers may use and output lists instead)

Recently I was brainstorming what a language with only (arbitrarily nested) sets would be like. A number is represented with a set of that many elements. The elements need to be different, which leads to this definition:

Definition

  • The set representation of $0$ is the empty set.
  • The set representation of any other integer $n$ is the set of the set representations of all positive integers less than $n$, including zero.
  • Negative, complex, or rational numbers do not need to be handled.
  • Your full program or function is to convert from a positive integer to a set or list.

Examples

0 {}
1 {{}}
2 {{}, {{}}}
3 {{}, {{}}, {{}, {{}}}}
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Japt, 3 bytes

ÆßX

Try it online! (don't mind the -Q

This is Shaggy's solution.

ÆßX
Æ   Make a range [0, input) and map each number X:
 ß  Run this program again on
  X

Japt, 11 8 bytes

Saved 3 bytes thanks to Shaggy! (Shaggy also has a 3-byter ready)

gA=_o mA

Try it online!

This is practically a port of Razetime's answer, which you should upvote!

gA=_o mA
g        Apply the following function to the input
 A=      It's a recursive function, so assign it to the variable A
   _o    Make a range [0, Z), where Z is the input
      mA And map every number in that range to A again
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1 comment thread

Welcome (4 comments)
Welcome
Shaggy‭ wrote over 3 years ago

Welcome to Japt :) You can save 3 bytes here using one of Japt's own variables (i.e., an uppercase letter) to assign the function to, avoiding the need to switch in & out of JS. But you can get even shorter by using Japt's built-in recursion (ß) with o@ßX which can be further shortened with a shortcut to just ÆßX, tying you with Jelly.

user‭ wrote over 3 years ago

Shaggy‭ Wow! Are you sure you don't want to write that last one as your own answer?

Shaggy‭ wrote over 3 years ago

Not at all, @user; it's just your solution golfed down further. And I'd always much rather help out a newcomer to Japt to the rep I might get from posting something myself.

user‭ wrote over 3 years ago

Shaggy‭ Alright, thanks!