Fix wiggle sort (#991)

Co-authored-by: Antonia Strack <antonia.strack@thm.mni.de>

Sorts/test/SimplifiedWiggleSort.test.js

@@ -0,0 +1,24 @@
+import { simplifiedWiggleSort } from '../SimplifiedWiggleSort.js'
+
+describe('simplified wiggle sort', () => {
+  test('simplified wiggle sort for chars', () => {
+    const src = ['a', 'b', 'c']
+    expect(simplifiedWiggleSort(src)).toEqual(['a', 'c', 'b'])
+  })
+
+  test('wiggle sort with duplicates, even array', () => {
+    const src = [2, 2, 1, 3]
+    expect(simplifiedWiggleSort(src)).toEqual([1, 3, 2, 2])
+  })
+
+  test('wiggle sort with duplicates, odd array', () => {
+    const src = [1, 1, 1, 2, 4]
+    expect(simplifiedWiggleSort(src)).toEqual([1, 4, 1, 2, 1])
+  })
+
+  test('simplified wiggle sort which leads to equal values next to ' +
+    'each other', () => {
+    const src = [3, 3, 5, 1]
+    expect(simplifiedWiggleSort(src)).toEqual([1, 5, 3, 3])
+  })
+})