#include <stdio.h>
 
int main()
{
   int first, second, *p, *q, sum;
 
   printf("Enter two integers to add\n");
   scanf("%d%d", &first, &second);
 
   p = &first;
   q = &second;
 
   sum = *p + *q;
 
   printf("Sum of entered numbers = %d\n",sum);
 
   return 0;
}

-------------------------------------------------------------------------------
#include <stdio.h>
int main( )
{
   int val[7] = { 11, 22, 33, 44, 55, 66, 77 } ;
   /* for loop to print value and address of each element of array*/
   for ( int i = 0 ; i < 7 ; i++ )
   {
         printf("val[%d]: value is %d and address is %x", i, val[i], &val[i]);
   }
   return 0;
}
-------------------------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
int main(){
    int n,i,*ptr,sum=0;
    printf("Enter number of elements: ");
    scanf("%d",&n);
    ptr=(int*)malloc(n*sizeof(int));  //memory allocated using malloc
    if(ptr==NULL)                     
    {
        printf("Error! memory not allocated.");
        exit(0);
    }
    for(i=0;i<n;++i)
    {
		printf("Enter %d. elements of array: ",i+1);
        scanf("%d",ptr+i);
        sum+=*(ptr+i);
    }
    printf("Sum=%d\n",sum);
	printf("Before deallocation\n");
	for(i=0;i<n;++i)
    {
		printf("%d. elements of array: %u \n",i+1,*(ptr+i));
    }
	printf("After deallocation\n");
    free(ptr);
	for(i=0;i<n;++i)
    {
		printf("%d. elements of array: %u \n",i+1,*(ptr+i));
    }
    return 0;
}
-------------------------------------------------------------------------------