TrovaAntenatoComune

node TrovaAntenatoComune(node root, node first, node second)
    {
      node antenatoLeft = null;
      node antenatoRight = null;

      if (root.leftC != null)
      {
        if (root.leftC == first || root.leftC == second)
          antenatoLeft = root;
        else
          antenatoLeft = TrovaAntenatoComune(root.leftC, first, second);
      }

      if (root.rightC != null)
      {
        if (root.rightC == first || root.rightC == second)
          antenatoRight = root;
        else
          antenatoRight = TrovaAntenatoComune(root.rightC, first, second);
      }

      if (antenatoLeft == null)
        return antenatoRight;

      if (antenatoRight == null)
        return antenatoLeft;

      return root;
    }