Eliminar un Node dado en la lista enlazada bajo restricciones dadas

Dada una lista enlazada individualmente, escriba una función para eliminar un Node determinado. Su función debe seguir las siguientes restricciones: 
1) Debe aceptar un puntero al Node de inicio como primer parámetro y el Node a eliminar como segundo parámetro, es decir, un puntero al Node principal no es global. 
2) No debería devolver un puntero al Node principal. 
3) No debe aceptar puntero a puntero al Node principal.
Puede suponer que la lista enlazada nunca se vacía.
Deje que el nombre de la función sea deleteNode(). En una implementación sencilla, la función necesita modificar el puntero principal cuando el Node que se eliminará es el primer Node. Como se discutió en la publicación anterior , cuando una función modifica el puntero principal, la función debe usar uno de los enfoques dados, no podemos usar ninguno de esos enfoques aquí. 
Solución 
Manejamos explícitamente el caso cuando el Node que se va a eliminar es el primer Node, copiamos los datos del siguiente Node al encabezado y eliminamos el siguiente Node. Los casos en los que un Node eliminado no es el Node principal se pueden manejar normalmente encontrando el Node anterior y cambiando el siguiente del Node anterior. Las siguientes son las implementaciones. 
 

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C++

// C++ program to delete a given node
// in linked list under given constraints
#include <bits/stdc++.h>
using namespace std;
  
/* structure of a linked list node */
class Node 
{ 
    public:
    int data; 
    Node *next; 
}; 
  
void deleteNode(Node *head, Node *n) 
{ 
    // When node to be deleted is head node 
    if(head == n) 
    { 
        if(head->next == NULL) 
        { 
            cout << "There is only one node." <<
                    " The list can't be made empty "; 
            return; 
        } 
  
        /* Copy the data of next node to head */
        head->data = head->next->data; 
  
        // store address of next node 
        n = head->next; 
  
        // Remove the link of next node 
        head->next = head->next->next; 
  
        // free memory 
        free(n); 
  
        return; 
    } 
  
  
    // When not first node, follow 
    // the normal deletion process 
  
    // find the previous node 
    Node *prev = head; 
    while(prev->next != NULL && prev->next != n) 
        prev = prev->next; 
  
    // Check if node really exists in Linked List 
    if(prev->next == NULL) 
    { 
        cout << "\nGiven node is not present in Linked List"; 
        return; 
    } 
  
    // Remove node from Linked List 
    prev->next = prev->next->next; 
  
    // Free memory 
    free(n); 
  
    return; 
} 
  
/* Utility function to insert a node at the beginning */
void push(Node **head_ref, int new_data) 
{ 
    Node *new_node = new Node();
    new_node->data = new_data; 
    new_node->next = *head_ref; 
    *head_ref = new_node; 
} 
  
/* Utility function to print a linked list */
void printList(Node *head) 
{ 
    while(head!=NULL) 
    { 
        cout<<head->data<<" "; 
        head=head->next; 
    } 
    cout<<endl;
} 
  
/* Driver code */
int main() 
{ 
    Node *head = NULL; 
  
    /* Create following linked list 
    12->15->10->11->5->6->2->3 */
    push(&head,3); 
    push(&head,2); 
    push(&head,6); 
    push(&head,5); 
    push(&head,11); 
    push(&head,10); 
    push(&head,15); 
    push(&head,12); 
  
    cout<<"Given Linked List: "; 
    printList(head); 
  
    /* Let us delete the node with value 10 */
    cout<<"\nDeleting node "<< head->next->next->data<<" "; 
    deleteNode(head, head->next->next); 
  
    cout<<"\nModified Linked List: "; 
    printList(head); 
  
    /* Let us delete the first node */
    cout<<"\nDeleting first node "; 
    deleteNode(head, head); 
  
    cout<<"\nModified Linked List: "; 
    printList(head); 
    return 0; 
} 
  
// This code is contributed by rathbhupendra

C

#include <stdio.h>
#include <stdlib.h>
  
/* structure of a linked list node */
struct Node
{
    int data;
    struct Node *next;
};
  
void deleteNode(struct Node *head, struct Node *n)
{
    // When node to be deleted is head node
    if(head == n)
    {
        if(head->next == NULL)
        {
            printf("There is only one node. The list can't be made empty ");
            return;
        }
  
        /* Copy the data of next node to head */
        head->data = head->next->data;
  
        // store address of next node
        n = head->next;
  
        // Remove the link of next node
        head->next = head->next->next;
  
        // free memory
        free(n);
  
        return;
    }
  
  
    // When not first node, follow the normal deletion process
  
    // find the previous node
    struct Node *prev = head;
    while(prev->next != NULL && prev->next != n)
        prev = prev->next;
  
    // Check if node really exists in Linked List
    if(prev->next == NULL)
    {
        printf("\n Given node is not present in Linked List");
        return;
    }
  
    // Remove node from Linked List
    prev->next = prev->next->next;
  
    // Free memory
    free(n);
  
    return; 
}
  
/* Utility function to insert a node at the beginning */
void push(struct Node **head_ref, int new_data)
{
    struct Node *new_node =
        (struct Node *)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = *head_ref;
    *head_ref = new_node;
}
  
/* Utility function to print a linked list */
void printList(struct Node *head)
{
    while(head!=NULL)
    {
        printf("%d ",head->data);
        head=head->next;
    }
    printf("\n");
}
  
/* Driver program to test above functions */
int main()
{
    struct Node *head = NULL;
  
    /* Create following linked list
      12->15->10->11->5->6->2->3 */
    push(&head,3);
    push(&head,2);
    push(&head,6);
    push(&head,5);
    push(&head,11);
    push(&head,10);
    push(&head,15);
    push(&head,12);
  
    printf("Given Linked List: ");
    printList(head);
  
    /* Let us delete the node with value 10 */
    printf("\nDeleting node %d: ", head->next->next->data);
    deleteNode(head, head->next->next);
  
    printf("\nModified Linked List: ");
    printList(head);
  
    /* Let us delete the first node */
    printf("\nDeleting first node ");
    deleteNode(head, head);
  
    printf("\nModified Linked List: ");
    printList(head);
  
    getchar();
    return 0;
}

Python 3

# Node class
class Node:
  
    def __init__(self, data):
        self.data = data
        self.next = None
  
# LinkedList class
class LinkedList:
  
    def __init__(self):
        self.head = None
  
    def deleteNode(self, data):
        temp = self.head
        prev = self.head
        if temp.data == data:
            if temp.next is None:
                print("Can't delete the node as it has only one node")
            else:
                temp.data = temp.next.data
                temp.next = temp.next.next
            return
        while temp.next is not None and temp.data != data:
            prev = temp
            temp = temp.next
        if temp.next is None and temp.data !=data:
            print("Can't delete the node as it doesn't exist")
         # If node is last node of the linked list
        elif temp.next is None and temp.data == data:
            prev.next = None
        else:
            prev.next = temp.next
               
          
    # To push a new element in the Linked List     
    def push(self, new_data):
        new_node = Node(new_data)
        new_node.next = self.head
        self.head = new_node
  
    # To print all the elements of the Linked List
    def PrintList(self):
  
        temp = self.head
        while(temp):
            print(temp.data, end = " ")
            temp = temp.next
  
# Driver Code
llist = LinkedList()
llist.push(3)
llist.push(2)
llist.push(6)
llist.push(5)
llist.push(11)
llist.push(10)
llist.push(15)
llist.push(12)
  
print("Given Linked List: ", end = ' ')
llist.PrintList()
print("\n\nDeleting node 10:")
llist.deleteNode(10)
print("Modified Linked List: ", end = ' ')
llist.PrintList()
print("\n\nDeleting first node")
llist.deleteNode(12)
print("Modified Linked List: ", end = ' ')
llist.PrintList()
  
# This code is contributed by Akarsh Somani

Java

// Java program to delete a given node 
// in linked list under given constraints
  
class LinkedList {
  
    static Node head;
  
    static class Node {
  
        int data;
        Node next;
  
        Node(int d) {
            data = d;
            next = null;
        }
    }
  
    void deleteNode(Node node, Node n) {
          
        // When node to be deleted is head node
        if (node == n) {
            if (node.next == null) {
                System.out.println("There is only one node. The list "
                                 + "can't be made empty ");
                return;
            }
  
            /* Copy the data of next node to head */
            node.data = node.next.data;
  
            // store address of next node
            n = node.next;
  
            // Remove the link of next node
            node.next = node.next.next;
  
            // free memory
            System.gc();
  
            return;
        }
  
        // When not first node, follow the normal deletion process
        // find the previous node
        Node prev = node;
        while (prev.next != null && prev.next != n) {
            prev = prev.next;
        }
  
        // Check if node really exists in Linked List
        if (prev.next == null) {
            System.out.println("Given node is not present in Linked List");
            return;
        }
  
        // Remove node from Linked List
        prev.next = prev.next.next;
  
        // Free memory
        System.gc();
  
        return;
    }
  
    /* Utility function to print a linked list */
    void printList(Node head) {
        while (head != null) {
            System.out.print(head.data + " ");
            head = head.next;
        }
        System.out.println("");
    }
  
    public static void main(String[] args) {
        LinkedList list = new LinkedList();
        list.head = new Node(12);
        list.head.next = new Node(15);
        list.head.next.next = new Node(10);
        list.head.next.next.next = new Node(11);
        list.head.next.next.next.next = new Node(5);
        list.head.next.next.next.next.next = new Node(6);
        list.head.next.next.next.next.next.next = new Node(2);
        list.head.next.next.next.next.next.next.next = new Node(3);
  
        System.out.println("Given Linked List :");
        list.printList(head);
        System.out.println("");
          
        // Let us delete the node with value 10
        System.out.println("Deleting node :" + head.next.next.data);
        list.deleteNode(head, head.next.next);
  
        System.out.println("Modified Linked list :");
        list.printList(head);
        System.out.println("");
  
        // Let us delete the first node
        System.out.println("Deleting first Node");
        list.deleteNode(head, head);
        System.out.println("Modified Linked List");
        list.printList(head);
  
    }
}
  
// this code has been contributed by Mayank Jaiswal

C#

// C# program to delete a given 
// node in linked list under 
// given constraints
using System;
  
public class LinkedList 
{
  
    Node head;
  
    class Node 
    {
  
        public int data;
        public Node next;
  
        public Node(int d)
        {
            data = d;
            next = null;
        }
    }
  
    void deleteNode(Node node, Node n)
    {
          
        // When node to be deleted is head node
        if (node == n)
        {
            if (node.next == null) 
            {
                Console.WriteLine("There is only one node. The list "
                                + "can't be made empty ");
                return;
            }
  
            /* Copy the data of next node to head */
            node.data = node.next.data;
  
            // store address of next node
            n = node.next;
  
            // Remove the link of next node
            node.next = node.next.next;
  
            // free memory
            GC.Collect();
  
            return;
        }
  
        // When not first node, follow
        // the normal deletion process
        // find the previous node
        Node prev = node;
        while (prev.next != null && prev.next != n) 
        {
            prev = prev.next;
        }
  
        // Check if node really exists in Linked List
        if (prev.next == null) 
        {
            Console.WriteLine("Given node is not" +
                               "present in Linked List");
            return;
        }
  
        // Remove node from Linked List
        prev.next = prev.next.next;
  
        // Free memory
        GC.Collect();
  
        return;
    }
  
    /* Utility function to print a linked list */
    void printList(Node head) 
    {
        while (head != null)
        {
            Console.Write(head.data + " ");
            head = head.next;
        }
        Console.WriteLine("");
    }
  
    // Driver code
    public static void Main(String[] args)
    {
        LinkedList list = new LinkedList();
        list.head = new Node(12);
        list.head.next = new Node(15);
        list.head.next.next = new Node(10);
        list.head.next.next.next = new Node(11);
        list.head.next.next.next.next = new Node(5);
        list.head.next.next.next.next.next = new Node(6);
        list.head.next.next.next.next.next.next = new Node(2);
        list.head.next.next.next.next.next.next.next = new Node(3);
  
        Console.WriteLine("Given Linked List :");
        list.printList(list.head);
        Console.WriteLine("");
          
        // Let us delete the node with value 10
        Console.WriteLine("Deleting node :" +
                            list.head.next.next.data);
        list.deleteNode(list.head, list.head.next.next);
  
        Console.WriteLine("Modified Linked list :");
        list.printList(list.head);
        Console.WriteLine("");
  
        // Let us delete the first node
        Console.WriteLine("Deleting first Node");
        list.deleteNode(list.head, list.head);
        Console.WriteLine("Modified Linked List");
        list.printList(list.head);
    }
} 
  
// This code is contributed by Rajput-Ji

Javascript

<script>
// javascript program to delete a given node 
// in linked list under given constraints
var head;
  
     class Node
     {
            constructor(val)
            {
                this.data = val;
                this.next = null;
            }
        }
  
    function deleteNode( node,  n) 
    {
  
        // When node to be deleted is head node
        if (node == n)
        {
            if (node.next == null)
            {
                document.write("There is only one node. The list " + "can't be made empty ");
                return;
            }
  
            /* Copy the data of next node to head */
            node.data = node.next.data;
  
            // store address of next node
            n = node.next;
  
            // Remove the link of next node
            node.next = node.next.next;
  
            // free memory
          
  
            return;
        }
  
        // When not first node, follow the normal deletion process
        // find the previous node
         prev = node;
        while (prev.next != null && prev.next != n) 
        {
            prev = prev.next;
        }
  
        // Check if node really exists in Linked List
        if (prev.next == null)
        {
            document.write("Given node is not present in Linked List");
            return;
        }
  
        // Remove node from Linked List
        prev.next = prev.next.next;
        return;
    }
  
    /* Utility function to print a linked list */
    function printList( head)
    {
        while (head != null)
        {
            document.write(head.data + " ");
            head = head.next;
        }
        document.write("");
    }
      
        head = new Node(12);
        head.next = new Node(15);
        head.next.next = new Node(10);
        head.next.next.next = new Node(11);
        head.next.next.next.next = new Node(5);
        head.next.next.next.next.next = new Node(6);
        head.next.next.next.next.next.next = new Node(2);
        head.next.next.next.next.next.next.next = new Node(3);
  
        document.write("Given Linked List :");
        printList(head);
        document.write("");
  
        // Let us delete the node with value 10
        document.write("<br/>Deleting node :" + head.next.next.data);
        deleteNode(head, head.next.next);
  
        document.write("<br/>Modified Linked list :");
        printList(head);
        document.write("<br/>");
  
        // Let us delete the first node
        document.write("Deleting first Node<br/>");
        deleteNode(head, head);
        document.write("Modified Linked List");
        printList(head);
  
  
// This code is contributed by todaysgaurav
</script>

Producción: 
 

Given Linked List: 12 15 10 11 5 6 2 3

Deleting node 10:
Modified Linked List: 12 15 11 5 6 2 3

Deleting first node
Modified Linked List: 15 11 5 6 2 3

Complejidad de tiempo: O(n)

Como estamos recorriendo la lista solo una vez.

Espacio Auxiliar: O(1)

Como espacio adicional constante se utiliza.

Escriba comentarios si encuentra que los códigos/algoritmos anteriores son incorrectos o encuentra otras formas de resolver el mismo problema.
 

Publicación traducida automáticamente

Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA

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