Dada una lista enlazada individualmente, encuentre si la lista enlazada es circular o no. Una lista enlazada se llama circular si no termina en NULL y todos los Nodes están conectados en forma de ciclo. A continuación se muestra un ejemplo de una lista enlazada circular.
C++
// C++ program to check if linked list is circular
#include<bits/stdc++.h>
using namespace std;
/* Link list Node */
struct Node
{
int data;
struct Node* next;
};
/* This function returns true if given linked
list is circular, else false. */
bool isCircular(struct Node *head)
{
// An empty linked list is circular
if (head == NULL)
return true;
// Next of head
struct Node *node = head->next;
// This loop would stop in both cases (1) If
// Circular (2) Not circular
while (node != NULL && node != head)
node = node->next;
// If loop stopped because of circular
// condition
return (node == head);
}
// Utility function to create a new node.
Node *newNode(int data)
{
struct Node *temp = new Node;
temp->data = data;
temp->next = NULL;
return temp;
}
/* Driver program to test above function*/
int main()
{
/* Start with the empty list */
struct Node* head = newNode(1);
head->next = newNode(2);
head->next->next = newNode(3);
head->next->next->next = newNode(4);
isCircular(head)? cout << "Yes\n" :
cout << "No\n" ;
// Making linked list circular
head->next->next->next->next = head;
isCircular(head)? cout << "Yes\n" :
cout << "No\n" ;
return 0;
}
Java
// Java program to check if
// linked list is circular
import java.util.*;
class GFG
{
/* Link list Node */
static class Node
{
int data;
Node next;
}
/*This function returns true if given linked
list is circular, else false. */
static boolean isCircular( Node head)
{
// An empty linked list is circular
if (head == null)
return true;
// Next of head
Node node = head.next;
// This loop would stop in both cases (1) If
// Circular (2) Not circular
while (node != null && node != head)
node = node.next;
// If loop stopped because of circular
// condition
return (node == head);
}
// Utility function to create a new node.
static Node newNode(int data)
{
Node temp = new Node();
temp.data = data;
temp.next = null;
return temp;
}
/* Driver code*/
public static void main(String args[])
{
/* Start with the empty list */
Node head = newNode(1);
head.next = newNode(2);
head.next.next = newNode(3);
head.next.next.next = newNode(4);
System.out.print(isCircular(head)? "Yes\n" :
"No\n" );
// Making linked list circular
head.next.next.next.next = head;
System.out.print(isCircular(head)? "Yes\n" :
"No\n" );
}
}
// This code contributed by Arnab Kundu
Python3
# A simple Python program to check if a linked list is circular
# Node class
class Node:
# Function to initialise the node object
def __init__(self, data):
self.data = data # Assign data
self.next = None # Initialize next as null
# Linked List class contains a Node object
class LinkedList:
# Function to initialize head
def __init__(self):
self.head = None
def Circular(head):
if head==None:
return True
# Next of head
node = head.next
i = 0
# This loop would stop in both cases (1) If
# Circular (2) Not circular
while((node is not None) and (node is not head)):
i = i + 1
node = node.next
return(node==head)
# Code execution starts here
if __name__=='__main__':
llist = LinkedList()
llist.head = Node(1)
second = Node(2)
third = Node(3)
fourth = Node(4)
llist.head.next = second;
second.next = third;
third.next = fourth
if (Circular(llist.head)):
print('Yes')
else:
print('No')
fourth.next = llist.head
if (Circular(llist.head)):
print('Yes')
else:
print('No')
# This code is contributed by Sanket Badhe
C#
// C# program to check if
// linked list is circular
using System;
public class GFG
{
/* Link list Node */
public class Node
{
public int data;
public Node next;
}
/*This function returns true if given linked
list is circular, else false. */
static bool isCircular( Node head)
{
// An empty linked list is circular
if (head == null)
return true;
// Next of head
Node node = head.next;
// This loop would stop in both cases (1) If
// Circular (2) Not circular
while (node != null && node != head)
node = node.next;
// If loop stopped because of circular
// condition
return (node == head);
}
// Utility function to create a new node.
static Node newNode(int data)
{
Node temp = new Node();
temp.data = data;
temp.next = null;
return temp;
}
/* Driver code*/
public static void Main(String []args)
{
/* Start with the empty list */
Node head = newNode(1);
head.next = newNode(2);
head.next.next = newNode(3);
head.next.next.next = newNode(4);
Console.Write(isCircular(head)? "Yes\n" :
"No\n" );
// Making linked list circular
head.next.next.next.next = head;
Console.Write(isCircular(head)? "Yes\n" :
"No\n" );
}
}
// This code has been contributed by 29AjayKumar
Javascript
<script>
// javascript program to check if
// linked list is circular
/* Link list Node */
class Node {
constructor(val) {
this.data = val;
this.next = null;
}
}
/*
* This function returns true if given linked list is circular, else false.
*/
function isCircular( head) {
// An empty linked list is circular
if (head == null)
return true;
// Next of head
node = head.next;
// This loop would stop in both cases (1) If
// Circular (2) Not circular
while (node != null && node != head)
node = node.next;
// If loop stopped because of circular
// condition
return (node == head);
}
// Utility function to create a new node.
function newNode(data) {
temp = new Node();
temp.data = data;
temp.next = null;
return temp;
}
/* Driver code */
/* Start with the empty list */
head = newNode(1);
head.next = newNode(2);
head.next.next = newNode(3);
head.next.next.next = newNode(4);
document.write(isCircular(head) ? "Yes<br/>" : "No<br/>");
// Making linked list circular
head.next.next.next.next = head;
document.write(isCircular(head) ? "Yes<br/>" : "No<br/>");
// This code contributed by gauravrajput1
</script>
C
// C program to check if the linked list is circular
#include <stdio.h>
#include <stdlib.h>
struct Node {
int data;
struct Node* next;
};
int isCircular(struct Node* head)
{
// If linked list is empty it is circular
if (head == NULL)
return 1;
struct Node* ptr;
ptr = head->next;
// Traversing linked list till last node
while (ptr != NULL && ptr != head)
ptr = ptr->next;
// Condition for circular linked list
return (ptr == head);
}
// Function to create new Node
struct Node* newnode(int data)
{
struct Node* temp;
temp = (struct Node*)malloc(sizeof(struct Node));
temp->data = data;
temp->next = NULL;
return temp;
}
int main()
{
// code
// Starting with empty list
struct Node* head = newnode(1);
head->next = newnode(2);
head->next->next = newnode(3);
head->next->next->next = newnode(4);
// Checking for circular list
if (isCircular(head))
printf("Yes\n");
else
printf("No\n");
// If not circular making it circular
head->next->next->next->next = head;
if (isCircular(head))
printf("Yes\n");
else
printf("No\n");
return 0;
}
Publicación traducida automáticamente
Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA