Quicksort中的StackOverflow

Question

I'm getting a Stackoverflow if I try this code with numbers.length n = 100.000 ("." just for readability) and numbers being in inverse order so like 100.000 99.999 99.998 ... Is that normal? It works for smaller n like 10.000.

private void quickSort(int[] numbers, int l, int r) {
    if (l < r) {
      int p = numbers[r];
      int i = l - 1;
      int j = r;
      do {
        do {
          i++;
        } while (numbers[i] < p);
        do {
          j--;
        } while (j >= l && numbers[j] > p);
        if (i < j) {
          swap(numbers, i, j);
        }
      } while (i < j);
      swap(numbers, i, r);
      quickSort(numbers, l, i - 1);
      quickSort(numbers, i + 1, r);
    }
  }

Answer 1

You are probably making too many recursive calls, because the array is already sorted. You can allow JVM to use up more memory or change the maximum recursive depth. A better solution is to implement a non-recursive quicksort. Here's a Java example .