rotated-array-set

Set of (possibly rotated) arrays

Usage no npm install needed!

<script type="module">
  import rotatedArraySet from 'https://cdn.skypack.dev/rotated-array-set';
</script>

README

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rotated-array-set

RotatedArraySet is a class looking a bit like the built-in Set but is a set of arrays of T, and treats rotated arrays as "same".

API

Construct a RotatedArraySet, optionally provide a stringify method, converting T to string (this is not necessary for primitive types).

Versions

  • Since v2 this is a pure ESM package, and requires Node.js >=12.20. It cannot be used from CommonJS.

Example

import { RotatedArraySet } from 'rotated-array-set'

const tree = new RotatedArraySet< string >( );

tree.insert( [ 'a', 'b', 'c' ] );
tree.insert( [ 'x', 'y' ] );
tree.insert( [ 'c', 'a', 'b' ] ); // won't insert, already has this but rotated
tree.insert( [ 'y', 'x' ] ); // won't insert, same reason

tree.has( [ 'b', 'c', 'a' ] ); // true
tree.has( [ 'c', 'b', 'a' ] ); // false - this isn't *rotated*

tree.values( ); // [ [ 'a', 'b', 'c' ], [ 'x', 'y' ] ]

Provide a custom stringifier:

import { RotatedArraySet } from 'rotated-array-set'

const tree = new RotatedArraySet< User >( user => `${user.first} ${user.last}` );

tree.insert( [ user1, user2, user3 ] );
tree.insert( [ user3, user1, user2 ] ); // won't insert, already has this but rotated

tree.has( [ user2, user3, user1 ] ); // true
tree.has( [ user3, user2, user1 ] ); // false - not *rotated*

tree.values( ); // [ [ user1, user2, user3 ] ]