The difference between a linear representation of a stack and a linked implementation of a stack

A stack is a data structure that follows the LIFO (Last In First Out) principle. There are two common ways to implement a stack: linear representation and linked implementation.

1. Linear Representation of a Stack: In a linear representation, a stack is implemented using an array. The stack has a fixed size, which is determined at the time of its creation. The stack has a top pointer that keeps track of the top element in the stack. When an element is pushed onto the stack, it is placed at the position pointed to by the top pointer, and the top pointer is incremented. When an element is popped from the stack, the top pointer is decremented. If the stack is full and a push operation is attempted, it results in a stack overflow. If the stack is empty and a pop operation is attempted, it results in a stack underflow.

2. Linked Implementation of a Stack: In a linked implementation, a stack is implemented using a linked list. The stack can dynamically grow and shrink in size as elements are added or removed. The stack has a top pointer that points to the top element in the stack. When an element is pushed onto the stack, a new node is created and added to the front of the linked list, and the top pointer is updated to point to this new node. When an element is popped from the stack, the node at the front of the linked list is removed, and the top pointer is updated to point to the next node. There is no risk of stack overflow in a linked implementation, as long as the system has enough memory to allocate new nodes. However, a pop operation on an empty stack still results in a stack underflow.

In summary, the main difference between a linear representation and a linked implementation of a stack is that a linear representation has a fixed size and can result in a stack overflow, while a linked implementation can dynamically grow and shrink in size and does not risk a stack overflow.