Let T be a tree with n nodes. What is the running time of the function parenPrint(T, T.root())? (See Code Fragment 7.11)

void parenPrint(const Tree& T, const Position& p) { cout << *p; if (!p.isExternal()) { PositionList ch = p.children(); cout << "( "; for (Iterator q = ch.begin(); q != ch.end(); ++q) { if (q != ch.begin()) cout << " "; parenPrint(T, *q); } cout << " )"; } }