Question

not considering validity checks or other error checking, write the one line of linked list based stack code to implement push assuming pop removes from the front of the list.

Answer 1

A push operation in a linked list-based stack, omitting error checks and assuming pop removes from the front, would involve adding the new element to the front of the list.

Step-by-step explanation:

The correct answer is option push(head, value) where head is the reference to the top of the stack (front of the linked list) and value is the new data to be pushed onto the stack.

In a singly linked list where popping is done from the front, a push operation would involve adding the new element to the front as well, effectively making it the new head of the list. This operation can usually be done in O(1) time, since it doesn't require traversing the list.

The correct answer is option B. To implement the push operation in a linked list based stack, we need to insert a new node at the front of the list. Here is the one line of code to achieve this:

newNode->next = top; top = newNode;

This code creates a new node, sets its 'next' pointer to point to the current top node, and then updates 'top' to point to the new node. This effectively inserts the new node at the front of the list, pushing the previous top node down.