diff --git a/Sorts/FisherYatesShuffle.js b/Sorts/FisherYatesShuffle.js new file mode 100644 index 000000000..214cb5baa --- /dev/null +++ b/Sorts/FisherYatesShuffle.js @@ -0,0 +1,18 @@ +export const shuffle = (array) => { + let maxLength = array.length + let temp + let idx + + // While there remain elements to shuffle... + while (maxLength) { + // Pick a remaining element... + idx = Math.floor(Math.random() * maxLength--) + + // And swap it with the current element + temp = array[maxLength] + array[maxLength] = array[idx] + array[idx] = temp + } + + return array +} diff --git a/Sorts/test/FisherYatesShuffle.test.js b/Sorts/test/FisherYatesShuffle.test.js new file mode 100644 index 000000000..0971501a9 --- /dev/null +++ b/Sorts/test/FisherYatesShuffle.test.js @@ -0,0 +1,27 @@ +import { shuffle } from '../FisherYatesShuffle' + +describe('shuffle', () => { + it('expects to have a new array with same size', () => { + const fibonacci = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] + const mixedArray = shuffle(fibonacci) + + expect(mixedArray).toHaveLength(fibonacci.length) + }) + + it('expects to have a new array with same values', () => { + const fibonacci = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] + const mixedArray = shuffle(fibonacci) + + expect(mixedArray).toContain(0) + expect(mixedArray).toContain(1) + expect(mixedArray).toContain(2) + expect(mixedArray).toContain(3) + expect(mixedArray).toContain(5) + expect(mixedArray).toContain(8) + expect(mixedArray).toContain(13) + expect(mixedArray).toContain(21) + expect(mixedArray).toContain(34) + expect(mixedArray).toContain(55) + expect(mixedArray).toContain(89) + }) +})