Dada una lista enlazada circular. La tarea es escribir programas para eliminar Nodes de esta lista presente en:
- Primera posición.
- Ultima posicion.
- En cualquier puesto dado
.
Eliminación del primer Node de la lista enlazada circular única
Ejemplos :
Input : 99->11->22->33->44->55->66 Output : 11->22->33->44->55->66 Input : 11->22->33->44->55->66 Output : 22->33->44->55->66
Eliminación del primer Node de la lista enlazada circular
Enfoque :
- Tome dos punteros actuales y anteriores y recorra la lista.
- Mantenga el puntero actual fijo apuntando al primer Node y avance hasta llegar al último Node.
- Una vez que el puntero anterior llegue al último Node, haga lo siguiente:
- anterior->siguiente = actual->siguiente
- cabeza = anterior -> siguiente;
Función para eliminar el primer Node de la lista enlazada circular única :
C
// Function to delete First node of
// Circular Linked List
void DeleteFirst(struct Node** head)
{
struct Node *previous = *head, *firstNode = *head;
// check if list doesn't have any node
// if not then return
if (*head == NULL) {
printf("\nList is empty\n");
return;
}
// check if list have single node
// if yes then delete it and return
if (previous->next == previous) {
*head = NULL;
return;
}
// traverse second node to first
while (previous->next != *head) {
previous = previous->next;
}
// now previous is last node and
// first node(firstNode) link address
// put in last node(previous) link
previous->next = firstNode->next;
// make second node as head node
*head = previous->next;
free(firstNode);
return;
}
Java
// Function to delete First node of
// Circular Linked List
static void DeleteFirst(Node head)
{
Node previous = head, firstNode = head;
// Check if list doesn't have any node
// if not then return
if (head == null)
{
System.out.printf("\nList is empty\n");
return;
}
// Check if list have single node
// if yes then delete it and return
if (previous.next == previous)
{
head = null;
return;
}
// Traverse second node to first
while (previous.next != head)
{
previous = previous.next;
}
// Now previous is last node and
// first node(firstNode) link address
// put in last node(previous) link
previous.next = firstNode.next;
// Make second node as head node
head = previous.next;
System.gc();
return;
}
// This code is contributed by aashish1995
Python3
# Function delete First node of
# Circular Linked List
def DeleteFirst(head):
previous = head
next = head
# check list have any node
# if not then return
if (head == None) :
print("\nList is empty")
return None
# check list have single node
# if yes then delete it and return
if (previous.next == previous) :
head = None
return None
# traverse second to first
while (previous.next != head):
previous = previous.next
next = previous.next
# now previous is last node and
# next is first node of list
# first node(next) link address
# put in last node(previous) link
previous.next = next.next
# make second node as head node
head = previous.next
return head
# This code is contributed by shivanisinghss2110
C#
using System;
public class GFG{
static public// Function delete First node of
// Circular Linked List
static Node DeleteFirst(Node head)
{
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
Console.Write("\nList is empty\n");
return null;
}
// Check if list have single node
// if yes then delete it and return
if (previous.next == previous)
{
head = null;
return null;
}
// Traverse second node to first
while (previous.next != head)
{
previous = previous.next;
next = previous.next;
}
// Now previous is last node and
// first node(firstNode) link address
// put in last node(previous) link
previous.next = next.next;
// Make second node as head node
head = previous.next;
return head;
}
// This code is contributed by shivanisinghss2110.
c void Main (){
// Code
}
Javascript
<script>
function DeleteFirst(head)
{
previous = head, firstNode = head;
// Check if list doesn't have any node
// if not then return
if (head == null)
{
document.write("<br>List is empty<br>");
return;
}
// Check if list have single node
// if yes then delete it and return
if (previous.next == previous)
{
head = null;
return;
}
// Traverse second node to first
while (previous.next != head)
{
previous = previous.next;
}
// Now previous is last node and
// first node(firstNode) link address
// put in last node(previous) link
previous.next = firstNode.next;
// Make second node as head node
head = previous.next;
return;
}
// This code is contributed by rag2127
</script>
Eliminación del último Node de la Lista enlazada circular
Ejemplos :
Input : 99->11->22->33->44->55->66 Output : 99->11->22->33->44->55 Input : 99->11->22->33->44->55 Output : 99->11->22->33->44
Eliminar el último Node de la lista enlazada circular
Enfoque :
- Tome dos punteros actuales y anteriores y recorra la lista.
- Mueva ambos punteros de modo que el siguiente del anterior siempre apunte al actual. Siga moviendo los punteros actual y anterior hasta que actual llegue al último Node y anterior esté en el penúltimo Node.
- Una vez que la corriente del puntero llegue al último Node, haga lo siguiente:
- anterior->siguiente = actual->siguiente
- cabeza = anterior -> siguiente;
Función para eliminar el último Node de la lista :
C
// Function delete last node of
// Circular Linked List
void DeleteLast(struct Node** head)
{
struct Node *current = *head, *temp = *head, *previous;
// check if list doesn't have any node
// if not then return
if (*head == NULL) {
printf("\nList is empty\n");
return;
}
// check if list have single node
// if yes then delete it and return
if (current->next == current) {
*head = NULL;
return;
}
// move first node to last
// previous
while (current->next != *head) {
previous = current;
current = current->next;
}
previous->next = current->next;
*head = previous->next;
free(current);
return;
}
Java
// Function to delete last node of
// Circular Linked List
static Node DeleteLast(Node head)
{
Node current = head, temp = head, previous = null;
// Check if list doesn't have any node
// if not then return
if (head == null)
{
System.out.printf("\nList is empty\n");
return null;
}
// Check if list have single node
// if yes then delete it and return
if (current.next == current)
{
head = null;
return null;
}
// Move first node to last
// previous
while (current.next != head)
{
previous = current;
current = current.next;
}
previous.next = current.next;
head = previous.next;
return head;
}
// This code is contributed by pratham76
Python3
# Function to delete last node of
# Circular Linked List
def DeleteLast(head):
current = head
temp = head
previous = None
# check if list doesn't have any node
# if not then return
if (head == None):
print("\nList is empty")
return None
# check if list have single node
# if yes then delete it and return
if (current.next == current):
head = None
return None
# move first node to last
# previous
while (current.next != head):
previous = current
current = current.next
previous.next = current.next
head = previous.next
return head
# This code is contributed by rutvik_56
C#
// Function to delete last node of
// Circular Linked List
static Node DeleteLast(Node head)
{
Node current = head, temp = head, previous = null;
// check if list doesn't have any node
// if not then return
if (head == null)
{
Console.Write("\nList is empty\n");
return null;
}
// check if list have single node
// if yes then delete it and return
if (current.next == current)
{
head = null;
return null;
}
// move first node to last
// previous
while (current.next != head)
{
previous = current;
current = current.next;
}
previous.next = current.next;
head = previous.next;
return head;
}
// This code is contributed by shivanisinghss2110
Javascript
<script>
function DeleteLast(head)
{
let current = head, temp = head, previous = null;
// Check if list doesn't have any node
// if not then return
if (head == null)
{
document.write("<br>List is empty<br>");
return null;
}
// Check if list have single node
// if yes then delete it and return
if (current.next == current)
{
head = null;
return null;
}
// Move first node to last
// previous
while (current.next != head)
{
previous = current;
current = current.next;
}
previous.next = current.next;
head = previous.next;
return head;
}
// This code is contributed by avanitrachhadiya2155
</script>
Eliminación de Nodes en un índice dado en la lista enlazada circular
Ejemplos :
Input : 99->11->22->33->44->55->66
Index= 4
Output : 99->11->22->33->55->66
Input : 99->11->22->33->44->55->66
Index= 2
Output : 99->11->33->44->55->66
Nota : la indexación basada en 0 se considera para la lista.
Enfoque :
- Primero, encuentre la longitud de la lista. Es decir, el número de Nodes en la lista.
- Tome dos punteros anterior y actual para recorrer la lista. De tal manera que el anterior está una posición detrás del Node actual.
- Tome un recuento de variables inicializado en 0 para realizar un seguimiento de la cantidad de Nodes atravesados.
- Recorra la lista hasta alcanzar el índice dado.
- Una vez que se alcanza el índice dado, haga anterior->siguiente = actual->siguiente .
Función para eliminar un Node en un índice o ubicación dados de una lista enlazada circular única :
C
// Function to delete node at given index
// of Circular Linked List
void DeleteAtPosition(struct Node** head, int index)
{
// find length of list
int len = Length(*head);
int count = 1;
struct Node *previous = *head, *next = *head;
// check if list doesn't have any node
// if not then return
if (*head == NULL) {
printf("\nDelete Last List is empty\n");
return;
}
// given index is in list or not
if (index >= len || index < 0) {
printf("\nIndex is not Found\n");
return;
}
// delete first node
if (index == 0) {
DeleteFirst(head);
return;
}
// traverse first to last node
while (len > 0) {
// if index found delete that node
if (index == count) {
previous->next = next->next;
free(next);
return;
}
previous = previous->next;
next = previous->next;
len--;
count++;
}
return;
}
Java
// Java program to delete node at different
// Function delete node at a given position
// of Circular Linked List
static Node DeleteAtPosition( Node head, int index)
{
// Find length of list
int len = Length(head);
int count = 1;
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
System.out.printf("\nDelete Last List is empty\n");
return null;
}
// given index is in list or not
if (index >= len || index < 0)
{
System.out.printf("\nIndex is not Found\n");
return null;
}
// delete first node
if (index == 0)
{
head = DeleteFirst(head);
return head;
}
// traverse first to last node
while (len > 0)
{
// if index found delete that node
if (index == count)
{
previous.next = next.next;
return head;
}
previous = previous.next;
next = previous.next;
len--;
count++;
}
return head;
}
// This code is contributed by shivanisinghss2110
Python3
# Function delete node at a given position
# of Circular Linked List
def DeleteAtPosition(head, index):
# Find length of list
len = Length(head)
count = 1
previous = head
next = head
# check list have any node
# if not then return
if (head == None):
print("\nDelete Last List is empty")
return None
# given index is in list or not
if (index >= len or index < 0) :
print("\nIndex is not Found")
return None
# delete first node
if (index == 0) :
head = DeleteFirst(head)
return head
# traverse first to last node
while (len > 0):
# if index found delete that node
if (index == count):
previous.next = next.next
return head
previous = previous.next
next = previous.next
len = len - 1
count = count + 1
return head
# This code is contributed by shivanisinghss2110
Javascript
<script>
// Function delete node at a given position
// of Circular Linked List
function DeleteAtPosition(head, index){
// Find length of list
let len = head.length
let count = 1
let previous = head
let next = head
// check list have any node
// if not then return
if (head == null){
document.write("</br>","Delete Last List is empty")
return null
}
// given index is in list or not
if (index >= len || index < 0){
document.write("</br>","Index is not Found")
return null
}
// delete first node
if (index == 0){
head = DeleteFirst(head)
return head
}
// traverse first to last node
while (len > 0){
// if index found delete that node
if (index == count){
previous.next = next.next
return head
}
previous = previous.next
next = previous.next
len = len - 1
count = count + 1
}
return head
}
// This code is contributed by shinjanpatra
</script>
Programa que implementa las tres funciones anteriores
C++
// C++ program to delete node at different
// positions from a circular linked list
#include <bits/stdc++.h>
using namespace std;
// structure for a node
struct Node {
int data;
struct Node* next;
};
// Function to insert a node at the end of
// a Circular linked list
void Insert(struct Node** head, int data)
{
struct Node* current = *head;
// Create a new node
struct Node* newNode = new Node;
// check node is created or not
if (!newNode) {
printf("\nMemory Error\n");
return;
}
// insert data into newly created node
newNode->data = data;
// check list is empty
// if not have any node then
// make first node it
if (*head == NULL) {
newNode->next = newNode;
*head = newNode;
return;
}
// if list have already some node
else {
// move first node to last node
while (current->next != *head) {
current = current->next;
}
// put first or head node address
// in new node link
newNode->next = *head;
// put new node address into last
// node link(next)
current->next = newNode;
}
}
// Function print data of list
void Display(struct Node* head)
{
struct Node* current = head;
// if list is empty, simply show message
if (head == NULL) {
printf("\nDisplay List is empty\n");
return;
}
// traverse first to last node
else {
do {
printf("%d ", current->data);
current = current->next;
} while (current != head);
}
}
// Function return number of nodes present in list
int Length(struct Node* head)
{
struct Node* current = head;
int count = 0;
// if list is empty simply return length zero
if (head == NULL) {
return 0;
}
// traverse first to last node
else {
do {
current = current->next;
count++;
} while (current != head);
}
return count;
}
// Function delete First node of Circular Linked List
void DeleteFirst(struct Node** head)
{
struct Node *previous = *head, *next = *head;
// check list have any node
// if not then return
if (*head == NULL) {
printf("\nList is empty\n");
return;
}
// check list have single node
// if yes then delete it and return
if (previous->next == previous) {
*head = NULL;
return;
}
// traverse second to first
while (previous->next != *head) {
previous = previous->next;
next = previous->next;
}
// now previous is last node and
// next is first node of list
// first node(next) link address
// put in last node(previous) link
previous->next = next->next;
// make second node as head node
*head = previous->next;
free(next);
return;
}
// Function to delete last node of
// Circular Linked List
void DeleteLast(struct Node** head)
{
struct Node *current = *head, *temp = *head, *previous;
// check if list doesn't have any node
// if not then return
if (*head == NULL) {
printf("\nList is empty\n");
return;
}
// check if list have single node
// if yes then delete it and return
if (current->next == current) {
*head = NULL;
return;
}
// move first node to last
// previous
while (current->next != *head) {
previous = current;
current = current->next;
}
previous->next = current->next;
*head = previous->next;
free(current);
return;
}
// Function delete node at a given position
// of Circular Linked List
void DeleteAtPosition(struct Node** head, int index)
{
// Find length of list
int len = Length(*head);
int count = 1;
struct Node *previous = *head, *next = *head;
// check list have any node
// if not then return
if (*head == NULL) {
printf("\nDelete Last List is empty\n");
return;
}
// given index is in list or not
if (index >= len || index < 0) {
printf("\nIndex is not Found\n");
return;
}
// delete first node
if (index == 0) {
DeleteFirst(head);
return;
}
// traverse first to last node
while (len > 0) {
// if index found delete that node
if (index == count) {
previous->next = next->next;
free(next);
return;
}
previous = previous->next;
next = previous->next;
len--;
count++;
}
return;
}
// Driver Code
int main()
{
struct Node* head = NULL;
Insert(&head, 99);
Insert(&head, 11);
Insert(&head, 22);
Insert(&head, 33);
Insert(&head, 44);
Insert(&head, 55);
Insert(&head, 66);
// Deleting Node at position
printf("Initial List: ");
Display(head);
printf("\nAfter Deleting node at index 4: ");
DeleteAtPosition(&head, 4);
Display(head);
// Deleting first Node
printf("\n\nInitial List: ");
Display(head);
printf("\nAfter Deleting first node: ");
DeleteFirst(&head);
Display(head);
// Deleting last Node
printf("\n\nInitial List: ");
Display(head);
printf("\nAfter Deleting last node: ");
DeleteLast(&head);
Display(head);
return 0;
}
Java
// Java program to delete node at different
// positions from a circular linked list
import java.util.*;
import java.lang.*;
import java.io.*;
class GFG
{
// structure for a node
static class Node
{
int data;
Node next;
};
// Function to insert a node at the end of
// a Circular linked list
static Node Insert(Node head, int data)
{
Node current = head;
// Create a new node
Node newNode = new Node();
// check node is created or not
if (newNode == null)
{
System.out.printf("\nMemory Error\n");
return null;
}
// insert data into newly created node
newNode.data = data;
// check list is empty
// if not have any node then
// make first node it
if (head == null)
{
newNode.next = newNode;
head = newNode;
return head;
}
// if list have already some node
else
{
// move first node to last node
while (current.next != head)
{
current = current.next;
}
// put first or head node address
// in new node link
newNode.next = head;
// put new node address into last
// node link(next)
current.next = newNode;
}
return head;
}
// Function print data of list
static void Display( Node head)
{
Node current = head;
// if list is empty, simply show message
if (head == null)
{
System.out.printf("\nDisplay List is empty\n");
return;
}
// traverse first to last node
else
{
do
{
System.out.printf("%d ", current.data);
current = current.next;
} while (current != head);
}
}
// Function return number of nodes present in list
static int Length(Node head)
{
Node current = head;
int count = 0;
// if list is empty
// simply return length zero
if (head == null)
{
return 0;
}
// traverse first to last node
else
{
do
{
current = current.next;
count++;
} while (current != head);
}
return count;
}
// Function delete First node of
// Circular Linked List
static Node DeleteFirst(Node head)
{
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
System.out.printf("\nList is empty\n");
return null;
}
// check list have single node
// if yes then delete it and return
if (previous.next == previous)
{
head = null;
return null;
}
// traverse second to first
while (previous.next != head)
{
previous = previous.next;
next = previous.next;
}
// now previous is last node and
// next is first node of list
// first node(next) link address
// put in last node(previous) link
previous.next = next.next;
// make second node as head node
head = previous.next;
return head;
}
// Function to delete last node of
// Circular Linked List
static Node DeleteLast(Node head)
{
Node current = head, temp = head, previous=null;
// check if list doesn't have any node
// if not then return
if (head == null)
{
System.out.printf("\nList is empty\n");
return null;
}
// check if list have single node
// if yes then delete it and return
if (current.next == current)
{
head = null;
return null;
}
// move first node to last
// previous
while (current.next != head)
{
previous = current;
current = current.next;
}
previous.next = current.next;
head = previous.next;
return head;
}
// Function delete node at a given position
// of Circular Linked List
static Node DeleteAtPosition( Node head, int index)
{
// Find length of list
int len = Length(head);
int count = 1;
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
System.out.printf("\nDelete Last List is empty\n");
return null;
}
// given index is in list or not
if (index >= len || index < 0)
{
System.out.printf("\nIndex is not Found\n");
return null;
}
// delete first node
if (index == 0)
{
head = DeleteFirst(head);
return head;
}
// traverse first to last node
while (len > 0)
{
// if index found delete that node
if (index == count)
{
previous.next = next.next;
return head;
}
previous = previous.next;
next = previous.next;
len--;
count++;
}
return head;
}
// Driver Code
public static void main(String args[])
{
Node head = null;
head = Insert(head, 99);
head = Insert(head, 11);
head = Insert(head, 22);
head = Insert(head, 33);
head = Insert(head, 44);
head = Insert(head, 55);
head = Insert(head, 66);
// Deleting Node at position
System.out.printf("Initial List: ");
Display(head);
System.out.printf("\nAfter Deleting node at index 4: ");
head = DeleteAtPosition(head, 4);
Display(head);
// Deleting first Node
System.out.printf("\n\nInitial List: ");
Display(head);
System.out.printf("\nAfter Deleting first node: ");
head = DeleteFirst(head);
Display(head);
// Deleting last Node
System.out.printf("\n\nInitial List: ");
Display(head);
System.out.printf("\nAfter Deleting last node: ");
head = DeleteLast(head);
Display(head);
}
}
// This code is contributed by Arnab Kundu
Python3
# Python3 program to delete node at different
# positions from a circular linked list
# A linked list node
class Node:
def __init__(self, new_data):
self.data = new_data
self.next = None
self.prev = None
# Function to insert a node at the end of
# a Circular linked list
def Insert(head, data):
current = head
# Create a new node
newNode = Node(0)
# check node is created or not
if (newNode == None):
print("\nMemory Error\n")
return None
# insert data into newly created node
newNode.data = data
# check list is empty
# if not have any node then
# make first node it
if (head == None) :
newNode.next = newNode
head = newNode
return head
# if list have already some node
else:
# move first node to last node
while (current.next != head):
current = current.next
# put first or head node address
# in new node link
newNode.next = head
# put new node address into last
# node link(next)
current.next = newNode
return head
# Function print data of list
def Display(head):
current = head
# if list is empty, simply show message
if (head == None):
print("\nDisplay List is empty\n")
return
# traverse first to last node
else:
while(True):
print( current.data,end=" ")
current = current.next
if (current == head):
break;
# Function return number of nodes present in list
def Length(head):
current = head
count = 0
# if list is empty
# simply return length zero
if (head == None):
return 0
# traverse first to last node
else:
while(True):
current = current.next
count = count + 1
if (current == head):
break;
return count
# Function delete First node of
# Circular Linked List
def DeleteFirst(head):
previous = head
next = head
# check list have any node
# if not then return
if (head == None) :
print("\nList is empty")
return None
# check list have single node
# if yes then delete it and return
if (previous.next == previous) :
head = None
return None
# traverse second to first
while (previous.next != head):
previous = previous.next
next = previous.next
# now previous is last node and
# next is first node of list
# first node(next) link address
# put in last node(previous) link
previous.next = next.next
# make second node as head node
head = previous.next
return head
# Function to delete last node of
# Circular Linked List
def DeleteLast(head):
current = head
temp = head
previous = None
# check if list doesn't have any node
# if not then return
if (head == None):
print("\nList is empty")
return None
# check if list have single node
# if yes then delete it and return
if (current.next == current) :
head = None
return None
# move first node to last
# previous
while (current.next != head):
previous = current
current = current.next
previous.next = current.next
head = previous.next
return head
# Function delete node at a given position
# of Circular Linked List
def DeleteAtPosition(head, index):
# Find length of list
len = Length(head)
count = 1
previous = head
next = head
# check list have any node
# if not then return
if (head == None):
print("\nDelete Last List is empty")
return None
# given index is in list or not
if (index >= len or index < 0) :
print("\nIndex is not Found")
return None
# delete first node
if (index == 0) :
head = DeleteFirst(head)
return head
# traverse first to last node
while (len > 0):
# if index found delete that node
if (index == count):
previous.next = next.next
return head
previous = previous.next
next = previous.next
len = len - 1
count = count + 1
return head
# Driver Code
head = None
head = Insert(head, 99)
head = Insert(head, 11)
head = Insert(head, 22)
head = Insert(head, 33)
head = Insert(head, 44)
head = Insert(head, 55)
head = Insert(head, 66)
# Deleting Node at position
print("Initial List: ")
Display(head)
print("\nAfter Deleting node at index 4: ")
head = DeleteAtPosition(head, 4)
Display(head)
# Deleting first Node
print("\n\nInitial List: ")
Display(head)
print("\nAfter Deleting first node: ")
head = DeleteFirst(head)
Display(head)
# Deleting last Node
print("\n\nInitial List: ")
Display(head)
print("\nAfter Deleting last node: ")
head = DeleteLast(head)
Display(head)
# This code is contributed by Arnab Kundu
C#
// C# program to delete node at different
// positions from a circular linked list
using System;
class GFG
{
// structure for a node
class Node
{
public int data;
public Node next;
};
// Function to insert a node at the end of
// a Circular linked list
static Node Insert(Node head, int data)
{
Node current = head;
// Create a new node
Node newNode = new Node();
// check node is created or not
if (newNode == null)
{
Console.Write("\nMemory Error\n");
return null;
}
// insert data into newly created node
newNode.data = data;
// check list is empty
// if not have any node then
// make first node it
if (head == null)
{
newNode.next = newNode;
head = newNode;
return head;
}
// if list have already some node
else
{
// move first node to last node
while (current.next != head)
{
current = current.next;
}
// put first or head node address
// in new node link
newNode.next = head;
// put new node address into last
// node link(next)
current.next = newNode;
}
return head;
}
// Function print data of list
static void Display( Node head)
{
Node current = head;
// if list is empty, simply show message
if (head == null)
{
Console.Write("\nDisplay List is empty\n");
return;
}
// traverse first to last node
else
{
do
{
Console.Write("{0} ", current.data);
current = current.next;
} while (current != head);
}
}
// Function return number of nodes present in list
static int Length(Node head)
{
Node current = head;
int count = 0;
// if list is empty
// simply return length zero
if (head == null)
{
return 0;
}
// traverse first to last node
else
{
do
{
current = current.next;
count++;
} while (current != head);
}
return count;
}
// Function delete First node of
// Circular Linked List
static Node DeleteFirst(Node head)
{
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
Console.Write("\nList is empty\n");
return null;
}
// check list have single node
// if yes then delete it and return
if (previous.next == previous)
{
head = null;
return null;
}
// traverse second to first
while (previous.next != head)
{
previous = previous.next;
next = previous.next;
}
// now previous is last node and
// next is first node of list
// first node(next) link address
// put in last node(previous) link
previous.next = next.next;
// make second node as head node
head = previous.next;
return head;
}
// Function to delete last node of
// Circular Linked List
static Node DeleteLast(Node head)
{
Node current = head, temp = head, previous = null;
// check if list doesn't have any node
// if not then return
if (head == null)
{
Console.Write("\nList is empty\n");
return null;
}
// check if list have single node
// if yes then delete it and return
if (current.next == current)
{
head = null;
return null;
}
// move first node to last
// previous
while (current.next != head)
{
previous = current;
current = current.next;
}
previous.next = current.next;
head = previous.next;
return head;
}
// Function delete node at a given position
// of Circular Linked List
static Node DeleteAtPosition( Node head, int index)
{
// Find length of list
int len = Length(head);
int count = 1;
Node previous = head, next = head;
// check list have any node
// if not then return
if (head == null)
{
Console.Write("\nDelete Last List is empty\n");
return null;
}
// given index is in list or not
if (index >= len || index < 0)
{
Console.Write("\nIndex is not Found\n");
return null;
}
// delete first node
if (index == 0)
{
head = DeleteFirst(head);
return head;
}
// traverse first to last node
while (len > 0)
{
// if index found delete that node
if (index == count)
{
previous.next = next.next;
return head;
}
previous = previous.next;
next = previous.next;
len--;
count++;
}
return head;
}
// Driver Code
public static void Main(String []args)
{
Node head = null;
head = Insert(head, 99);
head = Insert(head, 11);
head = Insert(head, 22);
head = Insert(head, 33);
head = Insert(head, 44);
head = Insert(head, 55);
head = Insert(head, 66);
// Deleting Node at position
Console.Write("Initial List: ");
Display(head);
Console.Write("\nAfter Deleting node at index 4: ");
head = DeleteAtPosition(head, 4);
Display(head);
// Deleting first Node
Console.Write("\n\nInitial List: ");
Display(head);
Console.Write("\nAfter Deleting first node: ");
head = DeleteFirst(head);
Display(head);
// Deleting last Node
Console.Write("\n\nInitial List: ");
Display(head);
Console.Write("\nAfter Deleting last node: ");
head = DeleteLast(head);
Display(head);
}
}
// This code is contributed by Rajput-Ji
Javascript
<script>
// JavaScript program to delete node at different
// positions from a circular linked list
// A linked list node
class Node{
constructor(new_data){
this.data = new_data
this.next = null
this.prev = null
}
}
// Function to insert a node at the end of
// a Circular linked list
function Insert(head, data){
let current = head
// Create a new node
let newNode = new Node(0)
// check node is created or not
if (newNode == null){
document.write("</br>","Memory Error","</br>")
return null
}
// insert data into newly created node
newNode.data = data
// check list is empty
// if not have any node then
// make first node it
if (head == null){
newNode.next = newNode
head = newNode
return head
}
// if list have already some node
else{
// move first node to last node
while (current.next != head)
current = current.next
// put first or head node address
// in new node link
newNode.next = head
// put new node address into last
// node link(next)
current.next = newNode
}
return head
}
// Function document.write data of list
function Display(head){
let current = head
// if list is empty, simply show message
if (head == null){
document.write("</br>","Display List is empty","</br>")
return
}
// traverse first to last node
else{
while(true){
document.write( current.data," ")
current = current.next
if (current == head)
break;
}
}
}
// Function return number of nodes present in list
function Length(head){
let current = head
let count = 0
// if list is empty
// simply return length zero
if (head == null)
return 0
// traverse first to last node
else{
while(true){
current = current.next
count = count + 1
if (current == head)
break;
}
}
return count
}
// Function delete First node of
// Circular Linked List
function DeleteFirst(head){
let previous = head
let next = head
// check list have any node
// if not then return
if (head == null){
document.write("</br>","List is empty")
return null
}
// check list have single node
// if yes then delete it and return
if (previous.next == previous){
head = null
return null
}
// traverse second to first
while (previous.next != head){
previous = previous.next
next = previous.next
}
// now previous is last node and
// next is first node of list
// first node(next) link address
// put in last node(previous) link
previous.next = next.next
// make second node as head node
head = previous.next
return head
}
// Function to delete last node of
// Circular Linked List
function DeleteLast(head){
let current = head
let temp = head
let previous = null
// check if list doesn't have any node
// if not then return
if (head == null){
document.write("</br>","List is empty")
return null
}
// check if list have single node
// if yes then delete it and return
if (current.next == current){
head = null
return null
}
// move first node to last
// previous
while (current.next != head){
previous = current
current = current.next
}
previous.next = current.next
head = previous.next
return head
}
// Function delete node at a given position
// of Circular Linked List
function DeleteAtPosition(head, index){
// Find length of list
len = Length(head)
count = 1
previous = head
next = head
// check list have any node
// if not then return
if (head == null){
document.write("</br>","Delete Last List is empty")
return null
}
// given index is in list or not
if (index >= len || index < 0) {
document.write("</br>","Index is not Found")
return null
}
// delete first node
if (index == 0){
head = DeleteFirst(head)
return head
}
// traverse first to last node
while (len > 0){
// if index found delete that node
if (index == count){
previous.next = next.next
return head
}
previous = previous.next
next = previous.next
len = len - 1
count = count + 1
}
return head
}
// Driver Code
let head = null
head = Insert(head, 99)
head = Insert(head, 11)
head = Insert(head, 22)
head = Insert(head, 33)
head = Insert(head, 44)
head = Insert(head, 55)
head = Insert(head, 66)
// Deleting Node at position
document.write("Initial List: ")
Display(head)
document.write("</br>","After Deleting node at index 4: ")
head = DeleteAtPosition(head, 4)
Display(head)
// Deleting first Node
document.write("</br>","</br>","Initial List: ")
Display(head)
document.write("</br>","After Deleting first node: ")
head = DeleteFirst(head)
Display(head)
// Deleting last Node
document.write("</br>","</br>","Initial List: ")
Display(head)
document.write("</br>","After Deleting last node: ")
head = DeleteLast(head)
Display(head)
// This code is contributed by shinjanpatra
</script>
Producción:
Initial List: 99 11 22 33 44 55 66 After Deleting node at index 4: 99 11 22 33 55 66 Initial List: 99 11 22 33 55 66 After Deleting first node: 11 22 33 55 66 Initial List: 11 22 33 55 66 After Deleting last node: 11 22 33 55