//как-то так например
#include <cstdio>
#include <stddef.h>

int main(void)
{
	ptrdiff_t diff;
	int array[50];
	for(int i = 0; i<50; i++)
	{
		array[i]=i+1;
	}
	printf("first: %d, last: %d, firstptr: %p lastptr: %p\n",array[0], array[49], array, &array[49] );
	diff = &array[49] - &array[0];
	printf("arraysize is: %d , diff: %p, sizeof(int): %d", diff, diff, sizeof(int));
	return 0;
}