Cycle Detection in linked list

Cycle Detection in linked list

  May 10, 2017    

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We are having two nodes .
1 will go only one step and another for two and if they met means there is cycle else not


Code:
/*
Detect a cycle in a linked list. Note that the head pointer may be 'null' if the list is empty.

A Node is defined as:
    class Node {
        int data;
        Node next;
    }
*/

boolean hasCycle(Node head) {
if (head == null){
        return false;
    }

    Node slow = head;
    Node fast = head;

    while (fast != null && fast.next != null){
        slow = slow.next;
        fast = fast.next.next;

        if (slow == fast){
            return true;
        }
    }

    return false;
}