Circular Linked List | Set 2 (Traversal)
We have discussed Circular Linked List Introduction and Applications, in the previous post on Circular Linked List. In this post, traversal operation is discussed.
In a conventional linked list, we traverse the list from the head node and stop the traversal when we reach NULL. In a circular linked list, we stop traversal when we reach the first node again. Following is C code for linked list traversal.
C
/* Function to traverse a given Circular linked list and print nodes */void printList(struct Node *first){ struct Node *temp = first; // If linked list is not empty if (first != NULL) { // Keep printing nodes till we reach the first node again do { printf("%d ", temp->data); temp = temp->next; } while (temp != first); }} |
Java
/* Function to print nodes in agiven Circular linked list */static void printList(Node head){ Node temp = head; // If linked list is not empty if (head != null) { // Keep printing nodes till we reach the first node // again do { System.out.print(temp.data + " "); temp = temp.next; } while (temp != head); }}// This code is contributed by pratham76. |
C#
/* Function to print nodes in agiven Circular linked list */static void printList(Node head){ Node temp = head; // If linked list is not empty if (head != null) { // Keep printing nodes till we reach the first node // again do { Console.Write(temp.data + " "); temp = temp.next; } while (temp != head); }}//This code is contributed by rutvik_56 |
Complete program to demonstrate traversal. Following are complete programs to demonstrate traversal of circular linked list.
C++
// C++ program to implement // the above approach #include <bits/stdc++.h>using namespace std;/* structure for a node */class Node { public: int data; Node *next; }; /* Function to insert a node at the beginning of a Circular linked list */void push(Node **head_ref, int data) { Node *ptr1 = new Node(); Node *temp = *head_ref; ptr1->data = data; ptr1->next = *head_ref; /* If linked list is not NULL then set the next of last node */ if (*head_ref != NULL) { while (temp->next != *head_ref) temp = temp->next; temp->next = ptr1; } else ptr1->next = ptr1; /*For the first node */ *head_ref = ptr1; } /* Function to print nodes in a given Circular linked list */void printList(Node *head) { Node *temp = head; if (head != NULL) { do { cout << temp->data << " "; temp = temp->next; } while (temp != head); } } /* Driver program to test above functions */int main() { /* Initialize lists as empty */ Node *head = NULL; /* Created linked list will be 11->2->56->12 */ push(&head, 12); push(&head, 56); push(&head, 2); push(&head, 11); cout << "Contents of Circular Linked List\n "; printList(head); return 0; } // This is code is contributed by rathbhupendra |
C
// C program to implement// the above approach#include<stdio.h>#include<stdlib.h>/* structure for a node */struct Node{ int data; struct Node *next;};/* Function to insert a node at the beginning of a Circular linked list */void push(struct Node **head_ref, int data){ struct Node *ptr1 = (struct Node *)malloc(sizeof(struct Node)); struct Node *temp = *head_ref; ptr1->data = data; ptr1->next = *head_ref; /* If linked list is not NULL then set the next of last node */ if (*head_ref != NULL) { while (temp->next != *head_ref) temp = temp->next; temp->next = ptr1; } else ptr1->next = ptr1; /*For the first node */ *head_ref = ptr1;}/* Function to print nodes in a given Circular linked list */void printList(struct Node *head){ struct Node *temp = head; if (head != NULL) { do { printf("%d ", temp->data); temp = temp->next; } while (temp != head); }}/* Driver program to test above functions */int main(){ /* Initialize lists as empty */ struct Node *head = NULL; /* Created linked list will be 11->2->56->12 */ push(&head, 12); push(&head, 56); push(&head, 2); push(&head, 11); printf("Contents of Circular Linked List\n "); printList(head); return 0;} |
Java
// Java program to implement// the above approachclass GFG{// node static class Node{ int data; Node next;};/* Function to insert a nodeat the beginning of a Circularlinked list */static Node push(Node head_ref, int data){ Node ptr1 = new Node(); Node temp = head_ref; ptr1.data = data; ptr1.next = head_ref; /* If linked list is not null then set the next of last node */ if (head_ref != null) { while (temp.next != head_ref) temp = temp.next; temp.next = ptr1; } else ptr1.next = ptr1; head_ref = ptr1; return head_ref;}/* Function to print nodes in a given Circular linked list */static void printList(Node head){ Node temp = head; if (head != null) { do { System.out.print(temp.data + " "); temp = temp.next; } while (temp != head); }}// Driver Codepublic static void main(String args[]){ /* Initialize lists as empty */ Node head = null; /* Created linked list will be 11.2.56.12 */ head = push(head, 12); head = push(head, 56); head = push(head, 2); head = push(head, 11); System.out.println("Contents of Circular " + "Linked List:"); printList(head);}}// This code is contributed// by Arnab Kundu |
Python
# Python program to demonstrate # circular linked list traversal # Structure for a Nodeclass Node: # Constructor to create a new node def __init__(self, data): self.data = data self.next = Noneclass CircularLinkedList: # Constructor to create a empty circular linked list def __init__(self): self.head = None # Function to insert a node at the beginning of a # circular linked list def push(self, data): ptr1 = Node(data) temp = self.head ptr1.next = self.head # If linked list is not None then set the next of # last node if self.head is not None: while(temp.next != self.head): temp = temp.next temp.next = ptr1 else: ptr1.next = ptr1 # For the first node self.head = ptr1 # Function to print nodes in a given circular linked list def printList(self): temp = self.head if self.head is not None: while(True): print "%d" %(temp.data), temp = temp.next if (temp == self.head): break# Driver program to test above function# Initialize list as emptycllist = CircularLinkedList()# Created linked list will be 11->2->56->12cllist.push(12)cllist.push(56)cllist.push(2)cllist.push(11)print "Contents of circular Linked List"cllist.printList() # This code is contributed by # Nikhil Kumar Singh(nickzuck_007) |
C#
// C# program to implement // the above approach using System;class GFG { // node class Node { public int data; public Node next; }; /* Function to insert a node at the beginning of a Circular linked list */static Node push(Node head_ref, int data) { Node ptr1 = new Node(); Node temp = head_ref; ptr1.data = data; ptr1.next = head_ref; /* If linked list is not null then set the next of last node */ if (head_ref != null) { while (temp.next != head_ref) temp = temp.next; temp.next = ptr1; } else ptr1.next = ptr1; head_ref = ptr1; return head_ref; } /* Function to print nodes in a given Circular linked list */static void printList(Node head) { Node temp = head; if (head != null) { do { Console.Write(temp.data + " "); temp = temp.next; } while (temp != head); } } // Driver Code static public void Main(String []args) { /* Initialize lists as empty */ Node head = null; /* Created linked list will be 11.2.56.12 */ head = push(head, 12); head = push(head, 56); head = push(head, 2); head = push(head, 11); Console.WriteLine("Contents of Circular " + "Linked List:"); printList(head); } } // This code is contributed // by Arnab Kundu |
Output:
Contents of Circular Linked List 11 2 56 12
You may like to see following posts on Circular Linked List
Split a Circular Linked List into two halves
Sorted insert for circular linked list
We will soon be discussing the implementation of insert delete operations for circular linked lists.
Please write comments if you find any bug in above code/algorithm, or find other ways to solve the same problem
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