2017-02-12-isort-qsort.go

// This version of QuickSort reverts to InsertionSort when the
// slice size is below a certain cutoff value. The cutoff value
// is parametrizable.
func QuickSort(data Interface, l int, r int, cutoff int) {
  if l >= r {
    return
  }
  
  if r-l > cutoff {
    pivot := partition(data, l, r)
    QuickSort(data, l, pivot-1, cutoff)
    QuickSort(data, pivot+1, r, cutoff)
  } else {
    insertionSort(data, l, r)
  }
}