diff --git a/snippets/permuteAll.md b/snippets/permuteAll.md new file mode 100644 index 000000000..d6555210b --- /dev/null +++ b/snippets/permuteAll.md @@ -0,0 +1,42 @@ +### permuteAll + +Uses recursion and `Array.push()` to return all the permutations of the given input in an array. + +```js +const permuteAll = (input) => { + const result = []; + let inputState = input; + + if (typeof input === 'string') { + inputState = input.split(''); + } else if (typeof input === 'number') { + inputState = (input).toString().split(''); + } + + const permute = (arr, m = []) => { + if (arr.length === 0) { + result.push(m) + } else { + for (let i = 0; i < arr.length; i++) { + let curr = arr.slice(); + let next = curr.splice(i, 1); + permute(curr.slice(), m.concat(next)) + } + } + } + + permute(inputState); + + return (typeof input === 'string') + ? result.map(variant => variant.join('')) + : (typeof input === 'number') + ? result.map(variant => parseFloat(variant.join(''))) + : result; +} +``` + +```js +permuteAll('sun') // [ 'sun', 'snu', 'usn', 'uns', 'nsu', 'nus' ] +permuteAll([1, 33, 5]) // [ [ 1, 33, 5 ], [ 1, 5, 33 ], [ 33, 1, 5 ], [ 33, 5, 1 ], [ 5, 1, 33 ], [ 5, 33, 1 ] ] +permuteAll(345) // [ 345, 354, 435, 453, 534, 543 ] +```