Memory Allocation For Pointer

#include <stdio.h>

int main()
{
    
    int n, i, *ptr, sum = 0;

    printf("\n\nEnter number of elements: ");
    scanf("%d", &n);

    // dynamic memory allocation using malloc()
    ptr = (int *) malloc(n*sizeof(int));

    if(ptr == NULL)
    {
        printf("\n\nError! Memory not allocated\n");
        return 0;
    }

    printf("\n\nEnter elements of array: \n\n");
    for(i = 0; i < n; i++)
    {
        // storing elements at contiguous memory locations
        scanf("%d", ptr+i);    
        sum = sum + *(ptr + i);
    }

    // printing the array elements using pointer to the location
    printf("\n\nElements of the array are: ");
    for(i = 0; i < n; i++)
    {
        printf("%d  ",ptr[i]);
    }


    //remove allocate memory using free() method
    free(ptr);

    return 0;
}