2020-10-11 19:00:38 +02:00
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'use strict'
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const permutate = (aString) => {
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if (typeof aString !== 'string' || !aString) {
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throw new Error('The arg must be a valid, non empty string')
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}
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const characters = aString.split('')
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let permutations = [[characters.shift()]]
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while (characters.length) {
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const currentCharacter = characters.shift()
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2023-10-03 23:08:19 +02:00
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permutations = calculateCurrentCharacterPermutation(
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permutations,
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currentCharacter
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)
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2020-10-11 19:00:38 +02:00
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}
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return permutations
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2023-10-03 23:08:19 +02:00
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.map((character) => character.join(''))
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.filter((item, index, self) => self.indexOf(item) === index)
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2020-10-11 19:00:38 +02:00
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.sort()
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}
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2023-10-03 23:08:19 +02:00
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const calculateCurrentCharacterPermutation = (
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allPermutations,
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currentCharacter
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) => {
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2020-10-11 19:00:38 +02:00
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const currentPermutations = []
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2023-10-03 23:08:19 +02:00
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allPermutations.forEach((permutation) => {
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2020-10-11 19:00:38 +02:00
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let index = 0
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while (index <= permutation.length) {
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const tmp = [...permutation]
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tmp.splice(index, 0, currentCharacter)
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currentPermutations.push(tmp)
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index++
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}
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})
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return currentPermutations
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}
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export { permutate }
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