Koska a linkitetty lista kooltaan N jossa jokaisella solmulla on kaksi linkkiä: seuraava osoitin osoittaa seuraavaan solmuun ja satunnainen osoitin mihin tahansa luettelon satunnaiseen solmuun. Tehtävänä on luoda tästä linkitetystä listasta klooni O(1)-avaruuteen eli ilman ylimääräistä tilaa.
Esimerkkejä:
java listalaatikko
Syöte: Alla linkitetyn luettelon pää
Lähtö: Uusi linkitetty luettelo, joka on identtinen alkuperäisen luettelon kanssa.
[Odotettu lähestymistapa] lisäämällä solmut paikoilleen – O(3n) aika ja O(1) avaruus
Ajatuksena on luoda solmun kaksoiskappale ja erilliseen hash-taulukkoon tallentamisen sijaan voimme lisätä sen alkuperäisen solmun ja seuraavan solmun väliin. Nyt meillä on uusia solmuja vaihtoehtoisissa paikoissa. Nyt a solmu X sen kaksoiskappale tulee olemaan X-> seuraavaksi ja kaksoiskappaleen satunnaisen osoittimen tulee osoittaa X->satunnainen->seuraava (koska se on kopio X-> satunnainen ). Joten iteroi koko linkitetty luettelo päivittääksesi kaikkien kloonattujen solmujen satunnaisen osoittimen ja toista sitten uudelleen erottaaksesi alkuperäinen linkitetty luettelo ja kloonattu linkitetty luettelo.
Toteuta idea noudattamalla alla mainittuja vaiheita:
- Luo kopio kohteesta solmu 1 ja aseta se väliin solmu 1 ja solmu 2 luo kopio alkuperäisessä linkitetyssä luettelossa solmu 2 ja aseta se väliin 2 nd ja 3 rd solmu ja niin edelleen. Lisää kopio N:stä N:n peräänthsolmu
- Yhdistä kloonisolmu päivittämällä satunnaiset osoittimet.
- Erota kloonattu linkitetty luettelo alkuperäisestä luettelosta päivittämällä seuraavat osoittimet.
javan objekti
Alla on toteutus, jos yllä oleva lähestymistapa:
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);
Lähtö
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)
Aika monimutkaisuus: O(3n) koska käymme linkitetyn luettelon läpi kolme kertaa.
Aputila: O(1) koska tallennamme kaikki kloonatut solmut itse alkuperäiseen linkitettyyn luetteloon, lisätilaa ei tarvita.