Question

void firstNode

Write a function in c++ to insert element after P Activate Windos Go totivate Windows

Answer 1

`Hey,

Note: If you have any queries related to the answer please do comment. I would be very happy to resolve all your queries.

#include <bits/stdc++.h>
using namespace std;
  
// A linked list node
class Node
{
public:
int data;
Node *next;
};
  
/* Given a reference (pointer to pointer)
to the head of a list and an int, inserts
a new node on the front of the list. */
void push(Node** head_ref, int new_data)
{
/* 1. allocate node */
Node* new_node = new Node();
  
/* 2. put in the data */
new_node->data = new_data;
  
/* 3. Make next of new node as head */
new_node->next = (*head_ref);
  
/* 4. move the head to point to the new node */
(*head_ref) = new_node;
}
  
/* Given a node prev_node, insert a new node after the given
prev_node */
void insertAfter(Node* prev_node, int new_data)
{
/*1. check if the given prev_node is NULL */
if (prev_node == NULL)
{
cout<<"the given previous node cannot be NULL";
return;
}
  
/* 2. allocate new node */
Node* new_node = new Node();
  
/* 3. put in the data */
new_node->data = new_data;
  
/* 4. Make next of new node as next of prev_node */
new_node->next = prev_node->next;
  
/* 5. move the next of prev_node as new_node */
prev_node->next = new_node;
}
  
/* Given a reference (pointer to pointer) to the head
of a list and an int, appends a new node at the end */
void append(Node** head_ref, int new_data)
{
/* 1. allocate node */
Node* new_node = new Node();
  
Node *last = *head_ref; /* used in step 5*/
  
/* 2. put in the data */
new_node->data = new_data;
  
/* 3. This new node is going to be
the last node, so make next of
it as NULL*/
new_node->next = NULL;
  
/* 4. If the Linked List is empty,
then make the new node as head */
if (*head_ref == NULL)
{
*head_ref = new_node;
return;
}
  
/* 5. Else traverse till the last node */
while (last->next != NULL)
last = last->next;
  
/* 6. Change the next of last node */
last->next = new_node;
return;
}
  
// This function prints contents of
// linked list starting from head
void printList(Node *node)
{
while (node != NULL)
{
cout<<" "<<node->data;
node = node->next;
}
}
  
/* Driver code*/
int main()
{
/* Start with the empty list */
Node* head = NULL;
  
// Insert 6. So linked list becomes 6->NULL
append(&head, 6);
  
// Insert 7 at the beginning.
// So linked list becomes 7->6->NULL
push(&head, 7);
  
// Insert 1 at the beginning.
// So linked list becomes 1->7->6->NULL
push(&head, 1);
  
// Insert 4 at the end. So
// linked list becomes 1->7->6->4->NULL
append(&head, 4);
  
// Insert 8, after 7. So linked
// list becomes 1->7->8->6->4->NULL
insertAfter(head->next, 8);
  
cout<<"Created Linked list is: ";
printList(head);
  
return 0;
}

main.cpp Ctrl+S טש1 upper oreuu, 0); me. // Insert 7 at the beginning. // So linked list becomes 7->6->NULL push(head, 7); 107 108 109 110 111 112 113 114 115 116 117 // Insert 1 at the beginning. // So linked list becomes 1->7->6->NULL push(head, 1); // Insert 4 at the end. So // linked list becomes 1->7->6->4->NULL append(head, 4); 118 119 120 121 122 123 124 125 // Insert 8, after 7. So linked // list becomes 1->7->8->6->4->NULL insertAfterChead->next, 8); cout<<"Created Linked list is: "; printList(head); 126 127 return 0; 128 } input Created Linked list is: 1 7 8 6 4

Kindly revert for any queries

Thanks.