for Schleife in main() wird nicht ausgefuehrt

#include <stdio.h>
#include <stdlib.h>


void quicksort(int *A, int len);


int heaparray[100];
int max (int *a, int n, int i, int j, int k) 
{
    int m = i;
    if (j < n && a[j] > a[m]) {
        m = j;
    }
    if (k < n && a[k] > a[m]) {
        m = k;
    }
    return m;
}
void downheap (int *a, int n, int i) 
{
    while (1) {
        int j = max(a, n, i, 2 * i + 1, 2 * i + 2);
        if (j == i) {
            break;
        }
        int t = a[i];
        a[i] = a[j];
        a[j] = t;
        i = j;
    }
}
void heapsort (int *a, int n) 
{
    int i;
    for (i = (n - 2) / 2; i >= 0; i--) {
        downheap(a, n, i);
    }
    for (i = 0; i < n; i++) {
        int t = a[n - i - 1];
        a[n - i - 1] = a[0];
        a[0] = t;
        downheap(a, n - i - 1, 0);
    }
}
void quicksort(int *A, int len)
{
  if (len < 2) return;
  int pivot = A[len / 2];
  int i, j;
  for (i = 0, j = len - 1; ; i++, j--)
  {
    while (A[i] < pivot) i++;
    while (A[j] > pivot) j--;
    if (i >= j) break;
    int temp = A[i];
    A[i]     = A[j];
    A[j]     = temp;
  }
  quicksort(A, i);
  quicksort(A + i, len - i);
}
int main () {
   	printf("\n Filling array with %lu elements \n",sizeof(heaparray));




    	for(int zf;zf<sizeof(heaparray);zf++)
	{
	int r = rand() % 20;	
	heaparray[zf]=r;
	printf("%d",r);
	}




	printf("\n\n ");
	printf("\nSorting..\n");
	printf("\n\n ");


	if(sizeof(heaparray) != sizeof(heaparray))
	return printf("Something went wrong during filling");


  	heapsort(heaparray,sizeof heaparray);
	printf("\n\n ");




	for(int zn;zn<sizeof(heaparray);zn++)
	{
	printf("%d",heaparray[zn]);
	}
    return 0;
}

int main() 
{
	int size=0;
	int *array;


	printf("Array-Groesse eingeben: ");
	scanf("%d", &size);


	// Allocate memory
	array = (int *) malloc(size * sizeof(int));


	if(array != NULL) 
	{
		printf("\nSpeicher ist reserviert\n");
		printf("\nFilling array.\n");
		for(int loop=0;loop<size;loop++)
		{
		int qrand=rand() %20;
		array[loop]=qrand;
		printf("%d",qrand);

		}
	}
	else 
	{
		printf("\nKein freier Speicher vorhanden.\n");
	}


	heapsort(array,size);
	int loop2;
	for(loop2=0;loop2<size;loop2++)
	{
	printf("%d",array[loop2]);
	}

	while(loop2<size)
        {
        printf("%d",array[loop2]);
	loop2++;
        }



	printf("\nSpeicher ist freigegeben\n");
	free(array);
	return 0;
}