detectCycleWithHashSet<T> function

bool detectCycleWithHashSet<T>(LinkedListNode<T>? head)

Detects cycle using hash set approach (alternative method)

head - The head of the linked list to check Returns true if a cycle exists, false otherwise

Time Complexity: O(n) where n is the length of the list Space Complexity: O(n) due to hash set

Implementation

bool detectCycleWithHashSet<T>(LinkedListNode<T>? head) {
  Set<LinkedListNode<T>> visited = {};
  LinkedListNode<T>? current = head;

  while (current != null) {
    if (visited.contains(current)) {
      return true;
    }
    visited.add(current);
    current = current.next;
  }

  return false;
}