void quickSort(char *v[], int left, int right)
{
  int i, last;
  void swap(char *v[], int i, int j);

  if (left >= right) {
    return;
  }
  swap(v, left, (left + right)/2);
  last = left;
  for (i = left+1; i <= right; i++) {
    if ((strcmp(v[i], v[left])) < 0)
      swap(v, ++last, i);
    swap(v, left, last);
    quickSort(v, left, last-1);
    quickSort(v, last+1, right);
  }
}
void swap(char *v[], int i, int j)
{
  char * temp;
  temp = v[i];
  v[i] = v[j];
  v[j] = temp;
}