We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Linked Lists: Detect a Cycle
  2. Discussions

Linked Lists: Detect a Cycle

  • vmarica
     + 29 comments

    Java solution using fast and slow pointers, no need for a HashSet.

    boolean hasCycle(Node head) {
    if (head == null) return false;
    
    Node slow = head;
    Node fast = head.next;
    while (slow != fast) {
        if (fast == null || fast.next == null) return false;
        
        slow = slow.next;
        fast = fast.next.next;
    }
    
    return true;
}