Merge pull request TheAlgorithms#719 from MrDoomy/feat/shuffle-algorithm

Added Fisher Yates Algorithm

Author: pomkarnath98

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
+}

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)
+  })
+})