Linked list is a data structure that consists of a sequence of data records such that in each record there is a field that contains a reference (i.e.,a link) to the next record in the sequence.
In case of normal stack,
-if a stack is too large,too many slots are wasted
-if a stack is too small,it may become full too early
To overcome this disadvantage,dynamic memory allocation method is used.
In this case,
-a single and simple linked list is used.
-initially top pointer is initialized to NULL.
-top pointer always points to first node of the list.
-In case of push operation,new node is added before first node setting top pointer to new first node.
-In case of pop operation,first node is deleted seting top pointer to next node in the list.