C Realloc kullanımı

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

int main()
{
    int *ptr, i , n1, n2;
    printf("Enter size of array: ");
    scanf("%d", &n1);

    ptr = (int*) malloc(n1 * sizeof(int));

    printf("Address of previously allocated memory: ");
    for(i = 0; i < n1; ++i)
         printf("%u\t",ptr + i);

    printf("\nEnter new size of array: ");
    scanf("%d", &n2);
    ptr = realloc(ptr, n2);
    for(i = 0; i < n2; ++i)
         printf("%u\t", ptr + i);
    return 0;
}