0. function quicksort(list) {
 1.   if (list.length < 2) {
 2.     return list;
 3.   }
 4. 
 5.   const pivot = random(list);
 6.   const less = list.filter(i => i < pivot);
 7.   const greater = list.filter(i => i > pivot);
 8. 
 9.   return [
10.     ...quicksort(less),
11.     pivot,
12.     ...quicksort(greater)
13.   ];
14. }