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Print linked list from middle into left-right order

Displaying middle left-right sequence

Here given code implementation process.

//C Program
//Print linked list from middle into left-right order
#include<stdio.h>
#include <stdlib.h> //for malloc function

//create structure
struct Node
{
  int data;
  struct Node*next;
};
//function prototype
void insert(struct Node**,int);
void display(struct Node*);
//insert Node element
void insert(struct Node**head,int value)

{
  //Create dynamic node
  struct Node*node=(struct Node*)malloc(sizeof(struct Node));
  if(node==NULL)
  {
    printf("Memory overflow\n");
  }else
  {
    node->data=value;
    node->next=NULL;
    if(*head==NULL)
    {
      *head=node;
    }else
    {
      struct Node*temp=*head;
      //find last node
      while(temp->next!=NULL)
      {
        temp=temp->next;
      }
      //add node at last possition
      temp->next=node;
    }
  }
}
//Display element of Node
void display(struct Node*temp)
{

  if(temp==NULL)
  {
    printf("Empty linked list");
  }
  while(temp!=NULL)
  {
    printf("%3d",temp->data);
    temp=temp->next;
  }
}
//Print linked list element in left-right order at middle position
void show(struct Node*head,struct Node*slow,struct Node**middle)
{

  if(head==NULL) return;

  if(head->next != NULL && head->next->next != NULL)
  {
    //Until the not get middle elements
    show(head->next->next,slow->next,middle);
  }
  else if(head->next!=NULL && head->next->next==NULL)
  {
    //When even number of elements
    *middle=(slow)->next;
  }
  
  printf("%3d",(slow)->data );

  if(*middle !=NULL)
  {
    printf("%3d",(*middle)->data );
    *middle=(*middle)->next;
  }
  else
  {
     *middle=slow->next;
  }
}
int main()
{
  //create node pointer
  struct Node*head=NULL;
  
  //insert element of linked list

  insert(&head,1);
  insert(&head,2);
  insert(&head,3);
  insert(&head,4);
  insert(&head,5);
  insert(&head,6);
  insert(&head,7);
  insert(&head,8);

  printf("\n Nodes :");
  //display all node
  display(head);
  printf("\n O / P :");

  struct Node*middle=NULL;
  
  show(head,head,&middle);

  //case 2
  struct Node*root=NULL;
  insert(&root,1);
  insert(&root,2);
  insert(&root,3);
  insert(&root,4);
  insert(&root,5);
  insert(&root,6);
  insert(&root,7);


  middle=NULL;

  printf("\n Nodes :");
  display(root);

  printf("\n O / P :");
  show(root,root,&middle);
  return 0;

}

Output

 Nodes :  1  2  3  4  5  6  7  8
 O / P :  4  5  3  6  2  7  1  8
 Nodes :  1  2  3  4  5  6  7
 O / P :  4  3  5  2  6  1  7
//C++ Program 
//Delete a node from linked list without head pointer
#include <iostream>
using namespace std;

//create structure
struct Node
{
  int data;
  struct Node*next;
};
class LinkedList
{

public:
  Node*head;//head pointer
  LinkedList();
  void insert(int);
  void display();
  void show( Node*, Node*, Node**);
};
LinkedList::LinkedList()
{
  head=NULL;
}
//insert node at end of linked list
void LinkedList::insert(int value)
{
    //Create dynamic node
  struct Node*node=new Node;
  if(node==NULL)
  {
    cout<<"Memory overflow\n";
  }else
  {
    node->data=value;
    node->next=NULL;
    if(head==NULL)
    {
      //base condition
      head=node;
    }else
    {
      Node*temp=head;
      while(temp->next!=NULL)
      {
        temp=temp->next;
      }
      //add newly node at last
      temp->next=node;
    }
  }
}
//display all node value in linked list
void LinkedList:: display()
{
  if(head==NULL)
  {
    cout<<"Empty linked list";
  }
  else
  {
    Node*temp=head;
    cout<<"\nLinked List : ";
    while(temp!=NULL)
    {
      //print node value
      cout<<temp->data<<"  ";
      temp=temp->next;
    }
    cout<<endl;
  }
}

//Print linked list element in left-right order at middle position
void LinkedList:: show( Node*head, Node*slow, Node**middle)
{

  if(head==NULL) return;

  if(head->next != NULL && head->next->next != NULL)
  {
    //Until the not get middle elements
    show(head->next->next,slow->next,middle);
  }
  else if(head->next!=NULL && head->next->next==NULL)
  {
    //When even number of elements
    *middle=(slow)->next;
  }
  
  cout<<slow->data << "  ";

  if(*middle !=NULL)
  {
    cout<<(*middle)->data<< "  ";
    *middle=(*middle)->next;
  }
  else
  {
    *middle=slow->next;
  }
}
int main()
{

  //create object
  LinkedList obj;
  //insert element of linked list

  obj.insert(1);
  obj.insert(2);
  obj.insert(3);
  obj.insert(4);
  obj.insert(5);
  obj.insert(6);
  obj.insert(7);
  obj.insert(8);

  //display all node
  obj.display();
  cout<<(" O / P :  ");

  Node*middle=NULL;
  
  obj.show(obj.head,obj.head,&middle);

  //case 2
  LinkedList root;
  root.insert(1);
  root.insert(2);
  root.insert(3);
  root.insert(4);
  root.insert(5);
  root.insert(6);
  root.insert(7);


  middle=NULL;

  root.display();

  cout<<(" O / P :  ");
  root.show(root.head,root.head,&middle);
  return 0;
}

Output

Linked List : 1  2  3  4  5  6  7  8  
 O / P :  4  5  3  6  2  7  1  8  
Linked List : 1  2  3  4  5  6  7  
 O / P :  4  3  5  2  6  1  7 
//Java Program
//Print linked list from middle into left-right order
public class LinkedList
{

  static class Node
  {
    int data;
    Node next;
  }
  public Node head,middle;
  //Class constructors
  LinkedList()
  {
    head=null;
    middle=null;
  } 
  //insert element
  public void insert(int value)
  {
    //Create  node
    Node node=new Node();
    node.data=value;
    node.next=null;
    if(head==null)
    {
      head=node;
    }
    else
    {
      Node temp=head;
      //find last node
      while(temp.next!=null)
      {
        temp=temp.next;
      }
      temp.next=node;
    }
    
  }
  //Display all Linked List elements
  public void display()
  {
    if(head!=null)
    {
      Node temp=head;
      while(temp!=null)
      {
        System.out.print("  "+temp.data);
        temp=temp.next;
      }
      System.out.println();
    }else
    {
      System.out.println("Empty Linked list"); 
    }
  }
  
  //Print linked list element in left-right order at middle position
  public void show( Node head, Node slow)
  {

    if(head==null) return;

    if(head.next != null && head.next.next != null)
    {
      //Until the not get middle elements
      show(head.next.next,slow.next);
    }
    else if(head.next!=null && head.next.next==null)
    {
      //When even number of elements
      middle = slow.next;
    }
    
    System.out.print("  "+slow.data);

    if( middle != null)
    {
      System.out.print("  "+middle.data);
      middle=( middle).next;
    }
    else
    {
      middle=slow.next;
    }
  }
  
  public void  left_right()
  {

    middle=null;

    show(head,head);
  }



  public static void main(String[] args) 
  {

    LinkedList obj=new LinkedList();
    obj.insert(1);
    obj.insert(2);
    obj.insert(3);
    obj.insert(4);
    obj.insert(5);
    obj.insert(6);
    obj.insert(7);
    obj.insert(8);

    System.out.println("\n Nodes :");
    //display all node
    obj.display();
    System.out.println(" O / P :");
    obj.left_right();

    //case 2
    LinkedList root=new LinkedList();
    root.insert(1);
    root.insert(2);
    root.insert(3);
    root.insert(4);
    root.insert(5);
    root.insert(6);
    root.insert(7);


    System.out.println("\n Nodes :");
    root.display();

    System.out.println(" O / P :");
    root.left_right();

  }
}

Output

 Nodes :
  1  2  3  4  5  6  7  8
 O / P :
  4  5  3  6  2  7  1  8
 Nodes :
  1  2  3  4  5  6  7
 O / P :
  4  3  5  2  6  1  7
#Python Program
#Print linked list from middle into left-right order
class Node:
  def __init__(self,data):
    self.data=data
    self.next=None

#Create Class LinkedList    
class LinkedList:
  def __init__(self):
    #Assign default value
    self.head=None
    self.middle=None

  #insert new node to linked list  
  def insert(self,data):
    node=Node(data)
    node.next=None
    if self.head==None:
      self.head=node
    else:
      temp=self.head
      while temp.next!=None:
          temp=temp.next
      #add node    
      temp.next=node

  def display(self):
    if(self.head==None):
      print("Empty Linked List")
      return

    temp=self.head
    
    while(temp!=None):
      print(temp.data,end="  ")
      temp=temp.next
  

  def show(self,head,slow):
    if(head==None) :
      return;

    if(head.next != None and head.next.next != None):
      #Until the not get middle elements
      self.show(head.next.next,slow.next);
    
    elif(head.next != None and head.next.next == None):
      #When even number of elements
      self.middle = slow.next;
    
    
    print(slow.data,end="  ");

    if(self.middle != None):
      print(self.middle.data,end="  ");
      self.middle = self.middle.next;
    
    else:
      self.middle=slow.next;
    
  
  
  def leftRight(self):

    self.middle=None;

    self.show(self.head,self.head);
  
      
    

def main():
    #Create Object of class Linked
    obj=LinkedList();
    obj.insert(1);
    obj.insert(2);
    obj.insert(3);
    obj.insert(4);
    obj.insert(5);
    obj.insert(6);
    obj.insert(7);
    obj.insert(8);

    print("\nNodes :");
    #display all node
    obj.display();
    print("\nO / P :");
    obj.leftRight();

    #case 2
    root=LinkedList();
    root.insert(1);
    root.insert(2);
    root.insert(3);
    root.insert(4);
    root.insert(5);
    root.insert(6);
    root.insert(7);


    print("\nNodes :");
    root.display();

    print("\nO / P :");
    root.leftRight();
if __name__=="__main__":
    main()

Output

Nodes :
1  2  3  4  5  6  7  8  
O / P :
4  5  3  6  2  7  1  8  
Nodes :
1  2  3  4  5  6  7  
O / P :
4  3  5  2  6  1  7 
//C# Program
//Print linked list from middle into left-right order

using System;
public class Node
{
  public int data;
  public Node next;
}

public class LinkedList
{


  public Node head,middle;
  //Class constructors
  LinkedList()
  {
    head=null;
    middle=null;
  } 
  //insert element
  public void insert(int value)
  {
    //Create  node
    Node node=new Node();
    node.data=value;
    node.next=null;
    if(head==null)
    {
      head=node;
    }
    else
    {
      Node temp=head;
      //find last node
      while(temp.next!=null)
      {
        temp=temp.next;
      }
      temp.next=node;
    }

  }
  //Display all Linked List elements
  public void display()
  {
    if(head!=null)
    {
      Node temp=head;
      while(temp!=null)
      {
        Console.Write("  "+temp.data);
        temp=temp.next;
      }
      Console.WriteLine();
    }else
    {
      Console.WriteLine("Empty Linked list"); 
    }
  }

  //Print linked list element in left-right order at middle position
  public void show( Node head, Node slow)
  {

    if(head==null) return;

    if(head.next != null && head.next.next != null)
    {
      //Until the not get middle elements
      show(head.next.next,slow.next);
    }
    else if(head.next!=null && head.next.next==null)
    {
      //When even number of elements
      middle = slow.next;
    }

    Console.Write("  "+slow.data);

    if( middle != null)
    {
      Console.Write("  "+middle.data);
      middle=( middle).next;
    }
    else
    {
      middle=slow.next;
    }
  }

  public void  left_right()
  {

    middle=null;

    show(head,head);
  }



  public static void Main(String[] args) 
  {

    LinkedList obj=new LinkedList();
    obj.insert(1);
    obj.insert(2);
    obj.insert(3);
    obj.insert(4);
    obj.insert(5);
    obj.insert(6);
    obj.insert(7);
    obj.insert(8);

    Console.WriteLine("\n Nodes :");
    //display all node
    obj.display();
    Console.WriteLine(" O / P :");
    obj.left_right();

    //case 2
    LinkedList root=new LinkedList();
    root.insert(1);
    root.insert(2);
    root.insert(3);
    root.insert(4);
    root.insert(5);
    root.insert(6);
    root.insert(7);


    Console.WriteLine("\n Nodes :");
    root.display();

    Console.WriteLine(" O / P :");
    root.left_right();

  }
}

Output

 Nodes :
  1  2  3  4  5  6  7  8
 O / P :
  4  5  3  6  2  7  1  8
 Nodes :
  1  2  3  4  5  6  7
 O / P :
  4  3  5  2  6  1  7

<?php
//Php program 
//Print linked list from middle into left-right order
class Node
{
  public $data;
  public $next;
  function __construct($data)
  {
    $this->data = $data;
    $this->next = NULL;
  }
}
class LinkedList
{

  public $head;
  public $middle;
  function __construct()
  {
    $head = NULL;
    $middle = NULL;
  }
    /*
    * Append the Given data value at end of linked list
    * Fun : insert
    * Parm: data value
    *@return None
    */
    function insert($data)
    {
      $newNode=new Node($data); 
      if($this->head==NULL)
      {
        $this->head=$newNode;
      }else
      {
        $temp=$this->head;
            //find last node of linked list
        while($temp->next!=NULL)
        {
          $temp=$temp->next;
        }
            //add new node to last of linked list
        $temp->next=$newNode;
      }
    }
        //Display all inserted node in linked list
    function display()
    {
      if($this->head==NULL)
      {
        echo "Empty Linked List";
      }
      else{
        $temp=$this->head;
        echo "\nLinked List :";
        while($temp!=NULL)
        {
          //display node value
          echo "  ".$temp->data;
          $temp=$temp->next; //visit to next node
        }
      }   
    }
    //Delete a node in linked list
    function delete_node($element)
    {
      if($element == NULL) return;

      if($element->next==NULL)
      {
        echo("\nNot Possible to delete Last node without head node\n");
      }
      else
      {

        $element->data = $element->next->data;

        $temp=$element->next;

        $element->next=$temp->next;

        if($this->head==$temp)
        {
        //when delete first node
        //You can also remove this condition
          $this->head=$this->head->next;
        }
        $temp=NULL;
      }
    }
    //Print linked list element in left-right order at middle position
    function show($head,$slow)
    {

      if($head==NULL) return;

      if($head->next != NULL && $head->next->next != NULL)
      {
        //Until the not get middle elements
        $this->show($head->next->next,$slow->next);
      }
      else if($head->next!=NULL && $head->next->next==NULL)
      {
        //When even number of elements
        $this->middle=$slow->next;
      }

      echo "  ".$slow->data;

      if($this->middle !=NULL)
      {
        echo "  ".$this->middle->data;
$this->middle=$this->middle->next;
}
else
{
  $this->middle= $slow->next;
}
}
function  left_right()
{

  $this->middle=NULL;

  $this->show($this->head,$this->head);
}

}


function main()
{
    //Make a object of LinkedList class
  $obj= new LinkedList();

    /*
    *Insert following nodes in linked list
    */
    $obj->insert(1);
    $obj->insert(2);
    $obj->insert(3);
    $obj->insert(4);
    $obj->insert(5);
    $obj->insert(6);
    $obj->insert(7);
    $obj->insert(8);

    //display all node
    $obj->display();
    echo ("\n O / P :  ");
    $obj->left_right();




    //Case 2
    $root=new LinkedList();
    $root->insert(1);
    $root->insert(2);
    $root->insert(3);
    $root->insert(4);
    $root->insert(5);
    $root->insert(6);
    $root->insert(7);

    $root->display();

    echo ("\n O / P :  ");
    $root->left_right();

  }
  main();
  ?>

Output

Linked List :  1  2  3  4  5  6  7  8
 O / P :    4  5  3  6  2  7  1  8
Linked List :  1  2  3  4  5  6  7
 O / P :    4  3  5  2  6  1  7
Last updated on by Kalkicode




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