Question

write a c++ member function that removes the first instance of a specific element in a linked list and then return the size of the list after the removal whether it was successful or not.

Answer 1

// CPP program to remove first node of
// linked list.
#include <iostream>
using namespace std;

/* Link list node */
struct Node {
   int data;
   struct Node* next;
};

/* Function to remove the first node
of the linked list */
Node* removeFirstNode(struct Node* head)
{
   if (head == NULL)
       return NULL;

   // Move the head pointer to the next node
   Node* temp = head;
   head = head->next;

   delete temp;

   return head;
}

// Function to push node at head
void push(struct Node** head_ref, int new_data)
{
   struct Node* new_node = new Node;
   new_node->data = new_data;
   new_node->next = (*head_ref);
   (*head_ref) = new_node;
}

// Driver code
int main()
{
   /* Start with the empty list */
   Node* head = NULL;

   /* Use push() function to construct
   the below list 8 -> 23 -> 11 -> 29 -> 12 */
   push(&head, 12);
   push(&head, 29);
   push(&head, 11);
   push(&head, 23);
   push(&head, 8);

   head = removeFirstNode(head);
   for (Node* temp = head; temp != NULL; temp = temp->next)
       cout << temp->data << " ";

   return 0;
}

length function:

int getCount(Node* head)

{

    int count = 0; // Initialize count

    Node* current = head; // Initialize current

    while (current != NULL)

    {

        count++;

        current = current->next;

    }

    return count;

}