Prerequisite:
- XOR Linked List – A Memory Efficient Doubly Linked List | Set 1
- XOR Linked List – A Memory Efficient Doubly Linked List | Set 2
An XOR linked list is a memory efficient doubly linked list in which the next pointer of every node stores the XOR of previous and next node’s address.
Given a singly linked list, the task is to convert the given singly list to a XOR linked list.
Approach: Since in XOR linked list each next pointer stores the XOR of prev and next nodes’s address. So the idea is to traverse the given singly linked list and keep track of the previous node in a pointer say prev.
Now, while traversing the list, change the next pointer of every node as:
current -> next = XOR(prev, current->next)
Printing the XOR linked list:
While printing XOR linked list we have to find the exact address of the next node every time. As we have seen above that the next pointer of every node stores the XOR value of prev and next node’s address. Therefore, the next node’s address can be obtained by finding XOR of prev and next pointer of current node in the XOR linked list.
So, to print the XOR linked list, traverse it by maintaining a prev pointer which stores the address of the previous node and to find the next node, calculate XOR of prev with next of current node.
Below is the implementation of the above approach:
// C++ program to Convert a Singly Linked // List to XOR Linked List #include <bits/stdc++.h> using namespace std;
// Linked List node struct Node {
int data;
struct Node* next;
}; // Utility function to create new node Node* newNode( int data)
{ Node* temp = new Node;
temp->data = data;
temp->next = NULL;
return temp;
} // Print singly linked list before conversion void print(Node* head)
{ while (head) {
// print current node
cout << head->data << " " ;
head = head->next;
}
cout << endl;
} // Function to find XORed value of // the node addresses Node* XOR(Node* a, Node* b) { return (Node*)(( uintptr_t )(a) ^ ( uintptr_t )(b));
} // Function to convert singly linked // list to XOR linked list void convert(Node* head)
{ Node* curr = head;
Node* prev = NULL;
Node* next = curr->next;
while (curr) {
// store curr->next in next
next = curr->next;
// change curr->next to XOR of prev and next
curr->next = XOR(prev, next);
// prev will change to curr for next iteration
prev = curr;
// curr is now pointing to next for next iteration
curr = next;
}
} // Function to print XORed linked list void printXOR(Node* head)
{ Node* curr = head;
Node* prev = NULL;
while (curr) {
// print current node
cout << curr->data << " " ;
Node* temp = curr;
/* compute curr as prev^curr->next as
it is previously set as prev^curr->next so
this time curr would be prev^prev^curr->next
which is curr->next */
curr = XOR(prev, curr->next);
prev = temp;
}
cout << endl;
} // Driver Code int main()
{ // Create following singly linked list
// 1->2->3->4
Node* head = newNode(1);
head->next = newNode(2);
head->next->next = newNode(3);
head->next->next->next = newNode(4);
cout << "Before Conversion : " << endl;
print(head);
convert(head);
cout << "After Conversion : " << endl;
printXOR(head);
return 0;
} |
// Java program to Convert a Singly Linked // List to XOR Linked List import java.io.*;
// Linked List node class Node
{ int data;
Node next;
// Utility function to create new node
Node( int item)
{
data = item;
next = null ;
}
} class GFG
{ public static Node root;
// Print singly linked list before conversion
static void print(Node head)
{
while (head != null )
{
// print current node
System.out.print(head.data + " " );
head = head.next;
}
System.out.println();
}
// Function to find XORed value of
// the node addresses
static Node XOR(Node a, Node b)
{
return b;
}
// Function to convert singly linked
// list to XOR linked list
static void convert(Node head)
{
Node curr = head;
Node prev = null ;
Node next = curr.next;
while (curr != null )
{
// store curr->next in next
next = curr.next;
// change curr->next to XOR of prev and next
curr.next = XOR(prev, next);
// prev will change to curr for next iteration
prev = curr;
// curr is now pointing to next for next iteration
curr = next;
}
}
// Function to print XORed linked list
static void printXOR(Node head)
{
Node curr = head;
Node prev = null ;
while (curr != null )
{
// print current node
System.out.print(curr.data + " " );
Node temp = curr;
/* compute curr as prev^curr->next as
it is previously set as prev^curr->next so
this time curr would be prev^prev^curr->next
which is curr->next */
curr = XOR(prev, curr.next);
prev = temp;
}
System.out.println();
}
// Driver Code
public static void main (String[] args)
{
// Create following singly linked list
// 1->2->3->4
GFG tree = new GFG();
tree.root = new Node( 1 );
tree.root.next = new Node( 2 );
tree.root.next.next = new Node( 3 );
tree.root.next.next.next = new Node( 4 );
System.out.println( "Before Conversion : " );
print(root);
convert(root);
System.out.println( "After Conversion : " );
printXOR(root);
}
} // This code is contributed by avanitrachhadiya2155 |
# Python3 program to Convert a Singly Linked # List to XOR Linked List # Linked List node class Node:
def __init__( self ,d):
self .data = d
self . next = None
# Print singly linked list before conversion def printt(head):
while (head):
# print current node
print (head.data, end = " " )
head = head. next
print ()
# Function to find XORed value of # the node addresses def XOR(a, b):
return b
# Function to convert singly linked # list to XOR linked list def convert(head):
curr = head
prev = None
next = curr. next
while (curr):
# store curr.next in next
next = curr. next
# change curr.next to XOR of prev and next
curr. next = XOR(prev, next )
# prev will change to curr for next iteration
prev = curr
# curr is now pointing to next for next iteration
curr = next
# Function to print XORed linked list def printXOR(head):
curr = head
prev = None
while (curr):
# print current node
print (curr.data, end = " " )
temp = curr
# /* compute curr as prev^curr.next as
# it is previously set as prev^curr.next so
# this time curr would be prev^prev^curr.next
# which is curr.next */
curr = XOR(prev, curr. next )
prev = temp
print ()
# Driver Code if __name__ = = '__main__' :
# Create following singly linked list
# 1.2.3.4
head = Node( 1 )
head. next = Node( 2 )
head. next . next = Node( 3 )
head. next . next . next = Node( 4 )
print ( "Before Conversion : " )
printt(head)
convert(head)
print ( "After Conversion : " )
printXOR(head)
# This code is contributed by mohitkumar29 |
using System;
class Node
{ public int data;
public Node next;
// Utility function to create new node
public Node( int item)
{
data = item;
next = null ;
}
} public class GFG
{ static Node root;
// Print singly linked list before conversion
static void print(Node head)
{
while (head != null )
{
// print current node
Console.Write(head.data + " " );
head = head.next;
}
Console.WriteLine();
}
// Function to find XORed value of
// the node addresses
static Node XOR(Node a, Node b)
{
return b;
}
// Function to convert singly linked
// list to XOR linked list
static void convert(Node head)
{
Node curr = head;
Node prev = null ;
Node next = curr.next;
while (curr != null )
{
// store curr->next in next
next = curr.next;
// change curr->next to XOR of prev and next
curr.next = XOR(prev, next);
// prev will change to curr for next iteration
prev = curr;
// curr is now pointing to next for next iteration
curr = next;
}
}
// Function to print XORed linked list
static void printXOR(Node head)
{
Node curr = head;
Node prev = null ;
while (curr != null )
{
// print current node
Console.Write(curr.data + " " );
Node temp = curr;
/* compute curr as prev^curr->next as
it is previously set as prev^curr->next so
this time curr would be prev^prev^curr->next
which is curr->next */
curr = XOR(prev, curr.next);
prev = temp;
}
Console.WriteLine();
}
// Driver Code
static public void Main ()
{
// Create following singly linked list
// 1->2->3->4
GFG.root = new Node(1);
GFG.root.next = new Node(2);
GFG.root.next.next = new Node(3);
GFG.root.next.next.next = new Node(4);
Console.WriteLine( "Before Conversion : " );
print(root);
convert(root);
Console.WriteLine( "After Conversion : " );
printXOR(root);
}
} // This code is contributed by rag2127 |
<script> // javascript program to Convert a Singly Linked // List to XOR Linked List// Linked List node class Node { // Utility function to create new node
constructor(val) {
this .data = val;
this .next = null ;
}
} var root;
// Print singly linked list before conversion
function print( head) {
while (head != null ) {
// print current node
document.write(head.data + " " );
head = head.next;
}
document.write( "<br/>" );
}
// Function to find XORed value of
// the node addresses
function XOR( a, b) {
return b;
}
// Function to convert singly linked
// list to XOR linked list
function convert( head) {
var curr = head;
var prev = null ;
var next = curr.next;
while (curr != null ) {
// store curr->next in next
next = curr.next;
// change curr->next to XOR of prev and next
curr.next = XOR(prev, next);
// prev will change to curr for next iteration
prev = curr;
// curr is now pointing to next for next iteration
curr = next;
}
}
// Function to print XORed linked list
function printXOR( head) {
var curr = head;
var prev = null ;
while (curr != null ) {
// print current node
document.write(curr.data + " " );
var temp = curr;
/*
* compute curr as prev^curr->next as it is previously set as prev^curr->next so
* this time curr would be prev^prev^curr->next which is curr->next
*/
curr = XOR(prev, curr.next);
prev = temp;
}
document.write();
}
// Driver Code
// Create following singly linked list
// 1->2->3->4
root = new Node(1);
root.next = new Node(2);
root.next.next = new Node(3);
root.next.next.next = new Node(4);
document.write( "Before Conversion : <br/>" );
print(root);
convert(root);
document.write( "After Conversion : <br/>" );
printXOR(root);
// This code contributed by gauravrajput1 </script> |
Before Conversion : 1 2 3 4 After Conversion : 1 2 3 4
Complexity Analysis:
- Time complexity: O(N) where N is no of nodes in given linked list
- Auxiliary Space: O(1)