C编程: Pointer arithmetics instead of index operations

Question

所以我对 C 编程非常陌生，在一个项目中，我得到了一个快速排序程序(我将在下面链接)，并要求我使用指针算术重写快速排序程序，即没有任何索引操作。我该怎么做呢？我应该在代码中做什么来实现指针算术而不是索引操作？ 我的代码在这里:http://ideone.com/ku9EhU

#include<stdio.h>
#define N 10

void quicksort(int a[], int low, int high);
int split(int a[], int low, int high);

int main(void)
{
  int a[N], i;

  printf("Enter %d numbers to be sorted: ", N);
  for (i = 0; i < N; i++)
    scanf("%d", &a[i]);

  quicksort(a, 0, N - 1);

  printf("In sorted order: ");
  for (i = 0; i < N; i++)
    printf("%d ", a[i]);
  printf("\n");

  return 0;
}

void quicksort(int a[], int low, int high)
{
  int middle;

  if (low >= high) return;
  middle = split(a, low, high);
  quicksort(a, low, middle - 1);
  quicksort(a, middle + 1, high);
}

int split(int a[], int low, int high)
{
  int part_element = a[low];

  for (;;) {
    while (low < high && part_element <= a[high])
      high--;
    if (low >= high) break;
    a[low++] = a[high];

    while (low < high && a[low] <= part_element)
      low++;
    if (low >= high) break;
    a[high--] = a[low];
  }

  a[high] = part_element;
  return high;
}

Answer 1

数组索引访问a[i]等于指针算术*(a + i)。