Loop invariant with no return value, is it possible? And program correctness

Vote count:

0

So I'm writing this program on linked list that reverse the user input, but I'm a bit lost whether is it possible to come up a loop invariants for types of loop where it doesn't return any value? For example a loop that is located inside main.

Here's an example of a loop to get user input inside main and store it in a linked list

int main(void){
char c = ' ';
Node* start = NULL; 
Node* temp; 
while(c!='.'){
    c=getchar();
    temp=(Node*)calloc(1, sizeof(Node));
    temp->x = c; 
    temp->next = start; 
    start = temp; 
}

Is it possible to come up with a loop invariant for this? Also what does it mean by program correctness and how do I proof it in my case?

Thanks!

asked 21 secs ago

Stud

6

Loop invariant with no return value, is it possible? And program correctness