30-seconds-of-code/powerset.md at 8f839542b61a6bb0188146c3f06be68a169c742d

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piyuesh b995e1bea1 prefixed Array. to reduce(), sort(), map() methods in snippets.

2017-12-13 17:41:45 +05:30

Use Array.reduce() combined with Array.map() to iterate over elements and combine into an array containing all combinations.

const powerset = arr =>
  arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
// powerset([1,2]) -> [[], [1], [2], [2,1]]