linkedlist.cpp

#include<iostream>
using namespace;
class Node  
{  
    public: 
    int data;  
    Node *next;  
};  
void push(Node** head_ref, int new_data)  
{  
    Node* new_node = new Node();  
 
    new_node->data = new_data;  
  
    new_node->next = (*head_ref);  
 
    (*head_ref) = new_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;  
    }  
 
    Node* new_node = new Node(); 
 
    new_node->data = new_data;  
  
    
    new_node->next = prev_node->next;  
 
    prev_node->next = 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;  
     /* 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 referance (pointer to pointer )to the head of a list and an int, apppends 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;
}
void printList(Node *node)  
{  
    while (node != NULL)  
    {  
        cout<<" "<<node->data;  
        node = node->next;  
    }  
}