Function quickSort

sorting/quick-sort.js:5–8

(array)

// space O(log n) because we need to use recursion and if we apply quick sort first on the smaller array that
// way we know that at most we will store log n calls on the call stack
function quickSort(array) {
  quickSortHelper(array, 0, array.length - 1);
  return array;
}

function quickSortHelper(array, startIdx, endIdx) {
  if (startIdx >= endIdx) return;