Program #36 (U4): Pointer Basics & Array Sum via Pointer Traversal
Task: Declare variables and print their addresses, then dereference to show values. Use a pointer to sum array elements.
#include <stdio.h>
int main(void){
int a = 10, b = 20;
int *pa = &a, *pb = &b;
printf("a=%d at %p\n", a, (void*)pa);
printf("b=%d at %p\n", b, (void*)pb);
printf("*pa=%d, *pb=%d\n", *pa, *pb);
int N, arr[200];
printf("Enter N (1..200): ");
if(scanf("%d", &N)!=1 || N<=0 || N>200){ printf("Invalid N.\n"); return 0; }
printf("Enter %d integers: ", N);
for(int i=0;i<N;++i) scanf("%d", &arr[i]);
long long sum = 0; int *p = arr, *end = arr + N;
for(; p<end; ++p) sum += *p;
printf("Sum = %lld\n", sum);
return 0;
}