QSort demo in C for Higher Order Function

CQsortDemo.cpp

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

void print_array(int* array, size_t size)
{
  for (unsigned i = 0; i < size; ++i)
  {
    printf("%d\n", *array++);
  }
}

int compare(const void* p, const void* q)
{
  int l = *(const int*)p;
  int r = *(const int*)q;

  return l - r;
}

int main()
{
  printf("QuickSort Demo..");
 
  int arr[] = { 7, 5, 22, 4, 3, 100, 19, 20 };
  int size = sizeof(arr) / sizeof(sizeof(arr[0]));

  printf("Before sort:\n");
  print_array(arr, size);

  qsort((void*)arr, size, sizeof(arr[0]), compare);

  printf("After sort:\n");
  print_array(arr, size);

  return 0;
}