Check if a linked list is Circular Linked List

The problem involves checking whether a given singly linked list is a circular linked list or not. In a circular linked list, the last node's next pointer points back to the first node, creating a closed loop.

Problem Statement

Given a singly linked list, we need to determine whether it's a circular linked list or not.

Example

Consider the following linked list: 1 -> 2 -> 3 -> 4 -> 5. This is not a circular linked list because the last node's next pointer is NULL. However, if we connect the last node's next pointer to the first node, it becomes a circular linked list: 1 -> 2 -> 3 -> 4 -> 5 -> 1.

Idea to Solve the Problem

To check if a linked list is a circular linked list, we can traverse the list while checking if the next pointer of the current node ever becomes NULL. If we encounter a NULL next pointer, it means the list is not circular. If we encounter a node whose next pointer points back to a previously visited node, it indicates that the list is circular.

Pseudocode

Here's the pseudocode to check if a linked list is circular:

function isCircular(linkedList):
    if linkedList.head is NULL:
        return 0
    
    temp = linkedList.head
    while temp is not NULL:
        temp = temp.next
        if temp is linkedList.head:
            return 1
        if temp is NULL:
            return 0

Algorithm Explanation

1. Check if the linked list is empty. If it's empty, return 0 (not circular).
2. Initialize temp to the head of the linked list.
3. Traverse the linked list using the temp pointer. If temp becomes equal to the head again, return 1 (circular).
4. If temp becomes NULL, return 0 (not circular).

Code Solution

1) Check linked list is circular or not in java 2) Check linked list is circular or not in c++ 3) Check linked list is circular or not in c 4) Check linked list is circular or not in c# 5) Check linked list is circular or not in vb.net 6) Check linked list is circular or not in php 7) Check linked list is circular or not in python 8) Check linked list is circular or not in ruby 9) Check linked list is circular or not in scala 10) Check linked list is circular or not in swift 11) Check linked list is circular or not in kotlin 12) Check linked list is circular or not in golang 13) Check linked list is circular or not in typescript 14) Check linked list is circular or not in node js

Time Complexity

The time complexity of checking whether a linked list is circular or not is O(n), where n is the number of nodes in the linked list. This is because we need to traverse the entire list to determine its circular nature.