Recursive insertion and traversal linked list
Last Updated :
23 Feb, 2023
We have discussed different methods of linked list insertion. How to recursively create a linked list?
Recursively inserting at the end: To create a Linked list using recursion follow these steps. Below steps insert a new node recursively at the end of linked list.
C++
Node* insertEnd(Node* head, int data)
{
if (head == NULL)
return newNode(data);
else
head->next = insertEnd(head->next, data);
return head;
}
|
Java
static Node insertEnd(Node head, int data)
{
if (head == null )
return newNode(data);
else
head.next = insertEnd(head.next, data);
return head;
}
|
Python3
def insertEnd(head, data):
if (head = = None ):
return newNode(data)
else :
head. next = insertEnd(head. next , data)
return head
|
C#
static Node insertEnd(Node head, int data)
{
if (head == null )
return newNode(data);
else
head.next = insertEnd(head.next, data);
return head;
}
|
Javascript
<script>
function insertEnd(head , data)
{
if (head == null )
{
return newNode(data);
}
else
{
head.next = insertEnd(head.next, data);
}
return head;
}
</script>
|
Time Complexity: O(N) where N is the number of nodes in given linked list.
Auxiliary Space: O(N) due to recursion call stack.
Recursively traversing the list:
The idea is simple, we print current node and recur for remaining list.
Implementation:
C++
void traverse(Node* head)
{
if (head == NULL)
return ;
cout << head->data << " " ;
traverse(head->next);
}
|
Java
static void traverse(Node head)
{
if (head == null )
return ;
System.out.print( head.data + " " );
traverse(head.next);
}
|
Python3
def traverse(head):
if (head = = None ):
return
print (head.data, end = " " );
traverse(head. next )
|
C#
static void traverse(Node head)
{
if (head == null )
return ;
Console.Write(head.data + " " );
traverse(head.next);
}
|
Javascript
function traverse(head){
if (head == null )
return ;
console.log(head.data + " " );
traverse(head.next);
}
|
Complete Program: Below is complete program to demonstrate working of insert and traverse a linked list.
C++
#include <bits/stdc++.h>
using namespace std;
struct Node {
int data;
Node* next;
};
Node *newNode( int data)
{
Node *new_node = new Node;
new_node->data = data;
new_node->next = NULL;
return new_node;
}
Node* insertEnd(Node* head, int data)
{
if (head == NULL)
return newNode(data);
else
head->next = insertEnd(head->next, data);
return head;
}
void traverse(Node* head)
{
if (head == NULL)
return ;
cout << head->data << " " ;
traverse(head->next);
}
int main()
{
Node* head = NULL;
head = insertEnd(head, 6);
head = insertEnd(head, 8);
head = insertEnd(head, 10);
head = insertEnd(head, 12);
head = insertEnd(head, 14);
traverse(head);
}
|
Java
public class GFG {
static class Node {
int data;
Node next;
};
static Node newNode( int data){
Node new_node = new Node();
new_node.data = data;
new_node.next = null ;
return new_node;
}
static Node insertEnd(Node head, int data){
if (head == null )
return newNode(data);
else
head.next = insertEnd(head.next, data);
return head;
}
static void traverse(Node head){
if (head == null )
return ;
System.out.print(head.data + " " );
traverse(head.next);
}
public static void main(String args[]){
Node head = null ;
head = insertEnd(head, 6 );
head = insertEnd(head, 8 );
head = insertEnd(head, 10 );
head = insertEnd(head, 12 );
head = insertEnd(head, 14 );
traverse(head);
}
}
|
Python3
import math
class Node:
def __init__( self , data):
self .data = data
self . next = None
def newNode(data):
new_node = Node(data)
new_node.data = data
new_node. next = None
return new_node
def insertEnd(head, data):
if (head = = None ):
return newNode(data)
else :
head. next = insertEnd(head. next , data)
return head
def traverse(head):
if (head = = None ):
return
print (head.data, end = " " );
traverse(head. next )
if __name__ = = '__main__' :
head = None
head = insertEnd(head, 6 )
head = insertEnd(head, 8 )
head = insertEnd(head, 10 )
head = insertEnd(head, 12 )
head = insertEnd(head, 14 )
traverse(head)
|
C#
using System;
class GFG
{
public class Node
{
public int data;
public Node next;
};
static Node newNode( int data)
{
Node new_node = new Node();
new_node.data = data;
new_node.next = null ;
return new_node;
}
static Node insertEnd(Node head, int data)
{
if (head == null )
return newNode(data);
else
head.next = insertEnd(head.next, data);
return head;
}
static void traverse(Node head)
{
if (head == null )
return ;
Console.Write(head.data + " " );
traverse(head.next);
}
public static void Main(String []args)
{
Node head = null ;
head = insertEnd(head, 6);
head = insertEnd(head, 8);
head = insertEnd(head, 10);
head = insertEnd(head, 12);
head = insertEnd(head, 14);
traverse(head);
}
}
|
Javascript
<script>
class Node
{
constructor(data) {
this .next = null ;
this .data = data;
}
}
function newNode(data)
{
let new_node = new Node(data);
return new_node;
}
function insertEnd(head, data)
{
if (head == null )
return newNode(data);
else
head.next = insertEnd(head.next, data);
return head;
}
function traverse(head)
{
if (head == null )
return ;
document.write(head.data + " " );
traverse(head.next);
}
let head = null ;
head = insertEnd(head, 6);
head = insertEnd(head, 8);
head = insertEnd(head, 10);
head = insertEnd(head, 12);
head = insertEnd(head, 14);
traverse(head);
</script>
|
Time Complexity: O(N), to traverse the linked list of size N.
Auxiliary Space: O(N), for recursion call stack
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