LeetCode - Linked List Cycle

Linked List Cycle

public boolean hasCycle(ListNode head) {
        if(head == null) return false;
        ListNode runner = head;
        ListNode walker = head;
        
        while(runner.next != null && runner.next.next != null){
            runner = runner.next.next;
            walker = walker.next;
            if(runner == walker){
                return true;
            }
        }
        
        return false;
    }