Assignment makes pointer without a cast - c

Question

I am editing a quick sort code so that the values of low, high, and middle point to an array element instead of integers.
This is my code:
#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, &a[0], &a[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 = *low;
for (;;) {
while (low < high && part_element <= *high)
high--;
if (low >= high) break;
*low++ = *high;
while (low < high && *low <= part_element)
low++;
if (low >= high) break;
*high-- = *low;
}
*high = part_element;
return *high;
}
I'm getting the error message:
qs.c:32:12: warning: assignment makes pointer from integer without a cast [enabled by default]
middle = split(a, low, high);
^
Can someone help me with this? Still a beginner at programming. All types of help are appreciated.

Answer 1

The problem is in this statement.
middle = split(a, low, high);
because middle is a pointer variable whereas split is a function which returns integer value not a pointer to an integer.
You are assigning integer value to a pointer variable middle .
You are not allowed to do that. :)
May be this will help you.

Answer 2

Change 'split()' to return an 'int *' instead of 'int'.
Change the last line of the 'split()' function from:
return *high;
to
return high;
Perhaps this would work better:
#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, &a[0], &a[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 = *low;
for (;;) {
while (low < high && part_element <= *high)
high--;
if (low >= high) break;
*low++ = *high;
while (low < high && *low <= part_element)
low++;
if (low >= high) break;
*high-- = *low;
}
*high = part_element;
return high;
}