Compte tenu d'un liste chaînée de taille N où chaque nœud a deux liens : pointeur suivant pointant vers le nœud suivant et pointeur aléatoire à n’importe quel nœud aléatoire de la liste. La tâche consiste à créer un clone de cette liste chaînée dans l'espace O(1), c'est-à-dire sans espace supplémentaire.
Exemples :
Saisir: Tête de la liste ci-dessous
dérivé partiel en latex
Sortir: Une nouvelle liste chaînée identique à la liste originale.
jeu de hachage Java
[Approche attendue] En insérant des nœuds sur place – O(3n) Time et O(1) Space
L'idée est de créer un double d'un nœud et au lieu de le stocker dans une table de hachage séparée, nous pouvons l'insérer entre le nœud d'origine et le nœud suivant. Nous aurons désormais de nouveaux nœuds à des positions alternatives. Maintenant pour un nœud X son duplicata sera X->suivant et le pointeur aléatoire du double doit pointer vers X->aléatoire->suivant (car c'est le double de X->aléatoire ). Par conséquent, parcourez toute la liste chaînée pour mettre à jour le pointeur aléatoire de tous les nœuds clonés, puis répétez à nouveau pour séparer la liste chaînée d'origine et la liste chaînée clonée.
Suivez les étapes mentionnées ci-dessous pour mettre en œuvre l'idée :
- Créer la copie de nœud 1 et insérez-le entre nœud 1 et nœud 2 dans la liste chaînée d'origine, créez la copie de nœud 2 et insérez-le entre 2 sd et 3 rd nœud et ainsi de suite. Ajouter la copie de N après le Nèmenœud
- Connectez le nœud clone en mettant à jour les pointeurs aléatoires.
- Séparez la liste chaînée clonée de la liste d'origine en mettant à jour les pointeurs suivants.
chaîne comparer c#
Vous trouverez ci-dessous la mise en œuvre de l'approche ci-dessus :
C++// C++ code to Clone a linked list with next and random // pointer by Inserting Nodes In-place #include
// Java code to Clone a linked list with next and random // pointer by Inserting Nodes In-place class Node { int data; Node next random; Node(int x) { data = x; next = random = null; } } class GfG { // Function to clone the linked list static Node cloneLinkedList(Node head) { if (head == null) { return null; } // Create new nodes and insert them next to the original nodes Node curr = head; while (curr != null) { Node newNode = new Node(curr.data); newNode.next = curr.next; curr.next = newNode; curr = newNode.next; } // Set the random pointers of the new nodes curr = head; while (curr != null) { if (curr.random != null) { curr.next.random = curr.random.next; } curr = curr.next.next; } // Separate the new nodes from the original nodes curr = head; Node clonedHead = head.next; Node clone = clonedHead; while (clone.next != null) { // Update the next nodes of original node // and cloned node curr.next = curr.next.next; clone.next = clone.next.next; // Move pointers of original and cloned // linked list to their next nodes curr = curr.next; clone = clone.next; } curr.next = null; clone.next = null; return clonedHead; } // Function to print the linked list public static void printList(Node head) { while (head != null) { System.out.print(head.data + '('); if (head.random != null) { System.out.print(head.random.data); } else { System.out.print('null'); } System.out.print(')'); if (head.next != null) { System.out.print(' -> '); } head = head.next; } System.out.println(); } public static void main(String[] args) { // Creating a linked list with random pointer Node head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(4); head.next.next.next.next = new Node(5); head.random = head.next.next; head.next.random = head; head.next.next.random = head.next.next.next.next; head.next.next.next.random = head.next.next; head.next.next.next.next.random = head.next; // Print the original list System.out.println('Original linked list:'); printList(head); // Function call Node clonedList = cloneLinkedList(head); System.out.println('Cloned linked list:'); printList(clonedList); } }
# Python code to Clone a linked list with next and random # pointer by Inserting Nodes In-place class Node: def __init__(self x): self.data = x self.next = None self.random = None # Function to clone the linked list def clone_linked_list(head): if head is None: return None # Create new nodes and insert them next to # the original nodes curr = head while curr is not None: new_node = Node(curr.data) new_node.next = curr.next curr.next = new_node curr = new_node.next # Set the random pointers of the new nodes curr = head while curr is not None: if curr.random is not None: curr.next.random = curr.random.next curr = curr.next.next # Separate the new nodes from the original nodes curr = head cloned_head = head.next clone = cloned_head while clone.next is not None: # Update the next nodes of original node # and cloned node curr.next = curr.next.next clone.next = clone.next.next # Move pointers of original as well as # cloned linked list to their next nodes curr = curr.next clone = clone.next curr.next = None clone.next = None return cloned_head # Function to print the linked list def print_list(head): while head is not None: print(f'{head.data}(' end='') if head.random: print(f'{head.random.data})' end='') else: print('null)' end='') if head.next is not None: print(' -> ' end='') head = head.next print() if __name__ == '__main__': # Creating a linked list with random pointer head = Node(1) head.next = Node(2) head.next.next = Node(3) head.next.next.next = Node(4) head.next.next.next.next = Node(5) head.random = head.next.next head.next.random = head head.next.next.random = head.next.next.next.next head.next.next.next.random = head.next.next head.next.next.next.next.random = head.next # Print the original list print('Original linked list:') print_list(head) # Function call cloned_list = clone_linked_list(head) print('Cloned linked list:') print_list(cloned_list)
// C# code to Clone a linked list with next and random // pointer by Inserting Nodes In-place using System; using System.Collections.Generic; public class Node { public int Data; public Node next Random; public Node(int x) { Data = x; next = Random = null; } } class GfG { static Node CloneLinkedList(Node head) { if (head == null) return null; // Create new nodes and insert them next to // the original nodes Node curr = head; while (curr != null) { Node newNode = new Node(curr.Data); newNode.next = curr.next; curr.next = newNode; curr = newNode.next; } // Set the random pointers of the new nodes curr = head; while (curr != null) { if (curr.Random != null) curr.next.Random = curr.Random.next; curr = curr.next.next; } // Separate the new nodes from the original nodes curr = head; Node clonedHead = head.next; Node clone = clonedHead; while (clone.next != null) { // Update the next nodes of original node // and cloned node curr.next = curr.next.next; clone.next = clone.next.next; // Move pointers of original as well as // cloned linked list to their next nodes curr = curr.next; clone = clone.next; } curr.next = null; clone.next = null; return clonedHead; } // Function to print the linked list static void PrintList(Node head) { while (head != null) { Console.Write(head.Data + '('); if (head.Random != null) Console.Write(head.Random.Data + ')'); else Console.Write('null)'); if (head.next != null) Console.Write(' -> '); head = head.next; } Console.WriteLine(); } public static void Main() { // Creating a linked list with random pointer Node head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(4); head.next.next.next.next = new Node(5); head.Random = head.next.next; head.next.Random = head; head.next.next.Random = head.next.next.next.next; head.next.next.next.Random = head.next.next; head.next.next.next.next.Random = head.next; // Print the original list Console.WriteLine('Original linked list:'); PrintList(head); Node clonedList = CloneLinkedList(head); Console.WriteLine('Cloned linked list:'); PrintList(clonedList); } }
// JavaScript code to Clone a linked list with next and random // pointer by Inserting Nodes In-place class Node { constructor(data) { this.data = data; this.next = null; this.random = null; } } function cloneLinkedList(head) { if (head === null) { return null; } // Create new nodes and insert them next to the // original nodes let curr = head; while (curr !== null) { let newNode = new Node(curr.data); newNode.next = curr.next; curr.next = newNode; curr = newNode.next; } // Set the random pointers of the new nodes curr = head; while (curr !== null) { if (curr.random !== null) { curr.next.random = curr.random.next; } curr = curr.next.next; } // Separate the new nodes from the original nodes curr = head; let clonedHead = head.next; let clone = clonedHead; while (clone.next !== null) { // Update the next nodes of original node and cloned node curr.next = curr.next.next; clone.next = clone.next.next; // Move pointers of original as well as cloned // linked list to their next nodes curr = curr.next; clone = clone.next; } curr.next = null; clone.next = null; return clonedHead; } // Function to print the linked list function printList(head) { let result = ''; while (head !== null) { result += head.data + '('; result += head.random ? head.random.data : 'null'; result += ')'; if (head.next !== null) { result += ' -> '; } head = head.next; } console.log(result); } // Creating a linked list with random pointer let head = new Node(1); head.next = new Node(2); head.next.next = new Node(3); head.next.next.next = new Node(4); head.next.next.next.next = new Node(5); head.random = head.next.next; head.next.random = head; head.next.next.random = head.next.next.next.next; head.next.next.next.random = head.next.next; head.next.next.next.next.random = head.next; // Print the original list console.log('Original linked list:'); printList(head); let clonedList = cloneLinkedList(head); console.log('Cloned linked list:'); printList(clonedList);
Sortir
Original linked list: 1(3) -> 2(1) -> 3(5) -> 4(3) -> 5(2) Cloned linked list: 1(3) -> 2(1) -> 3(5) -> 4(3) -> 5(2)
Complexité temporelle : O(3n) parce que nous parcourons la liste chaînée trois fois.
Espace auxiliaire : O(1) comme nous stockons tous les nœuds clonés dans la liste chaînée d'origine elle-même, aucun espace supplémentaire n'est requis.