Pointer List difficulty

Question

I just learned pointers and how to manually make a pointer list. I have something like this:
struct node{
int no;
node *next = NULL;
}

The algorithm to add an element to the end of the list looks something like this:

nod *s = f; // f is the pointer that points to the start of the list
while( s->next != NULL)
s = s->next;
s->next = new nod;
s->next->no = x; //x is a random integer to add to the list

Isn't it the same as this one:

nod *s = f; // f is the pointer that points to the start of the list
while( s != NULL)
s = s->next;
s = new nod;
s->no = x; //x is a random integer to add to the list

P.S. : The first algorithm works and the second doesn't. Why?

Answer 1

Thank you!