C Program: Checking whether a linked list is circular

bool IsCircular(Node* head)
{
      bool circleFound = false;
      bool tailFound = false;

      if (head && head->next)
     {
          Node* slower = head;
          Node* faster = head;

          do
          {
               slower = slower->next;
               faster =  faster->next->next;
               tailFound = ! (faster && faster->next);
               if ( ! tailFound )
               {
                   circleFound = (slower == faster || slower == faster->next);                                        
               }
          }
          while ( ! tailFound && ! circleFound)
     }

     return ( circleFound );
}