$(3$ points$)$ We can use a linked list to implement a stack. We assume that we use structure Node with two members to represent a node of the linked list. The member data stores the data, and the member next points to the next node in the linked list. Also we use a variable head to point to the first node of the linked list. head is initialized to NULL.

Pushing the value of a variable i into the stack can be implemented as follows.

newHead sizeof Node