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:
CPP
// C++ program to Convert a Singly Linked// List to XOR Linked List#include <bits/stdc++.h>using namespace std;// Linked List nodestruct Node { int data; struct Node* next;};// Utility function to create new nodeNode* newNode(int data){ Node* temp = new Node; temp->data = data; temp->next = NULL; return temp;}// Print singly linked list before conversionvoid print(Node* head){ while (head) { // print current node cout << head->data << " "; head = head->next; } cout << endl;}// Function to find XORed value of// the node addressesNode* XOR(Node* a, Node* b){ return (Node*)((uintptr_t)(a) ^ (uintptr_t)(b));}// Function to convert singly linked// list to XOR linked listvoid 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 listvoid 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 Codeint 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
// Java program to Convert a Singly Linked// List to XOR Linked Listimport java.io.*;// Linked List nodeclass 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
# Python3 program to Convert a Singly Linked# List to XOR Linked List# Linked List nodeclass Node: def __init__(self,d): self.data = d self.next = None# Print singly linked list before conversiondef printt(head): while (head): # print current node print(head.data, end=" ") head = head.next print()# Function to find XORed value of# the node addressesdef XOR(a, b): return b# Function to convert singly linked# list to XOR linked listdef 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 listdef 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 Codeif __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 |
C#
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 |
Javascript
<script>// javascript program to Convert a Singly Linked// List to XOR Linked List// Linked List nodeclass 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> |
Output
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)
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