8ee50178f3
Correct: `Array.from()` (it’s a static method) Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method) This patch uses the common `#` syntax to denote `.prototype.`.
14 lines
369 B
Markdown
14 lines
369 B
Markdown
### powerset
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Returns the powerset of a given array of numbers.
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Use `Array.prototype.reduce()` combined with `Array.prototype.map()` to iterate over elements and combine into an array containing all combinations.
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```js
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const powerset = arr => arr.reduce((a, v) => a.concat(a.map(r => [v].concat(r))), [[]]);
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```
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```js
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powerset([1, 2]); // [[], [1], [2], [2, 1]]
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```
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