/** * @file S2OJ/1974/std.cpp * @author Baoshuo * @url https://baoshuo.ren * @date 2023-03-30 * @license GPL-3.0 */ #include #include #include #include #include using std::cin; using std::cout; const char endl = '\n'; template > class LeftistTree : public std::enable_shared_from_this> { public: using pointer_type = std::shared_ptr>; protected: static Compare comp; private: size_t dist; pointer_type lchild, rchild; std::weak_ptr> root; public: T id, val; LeftistTree(const T& _val = 0, const T& _id = 0) : dist(0), lchild(nullptr), rchild(nullptr), root(), id(_id), val(_val) {} pointer_type find_root() { std::stack st; pointer_type cur = this->shared_from_this(); st.emplace(cur); while (auto ptr = cur->root.lock()) { st.emplace(cur = ptr); } while (!st.empty()) { auto ptr = st.top(); st.pop(); ptr->root = cur; } cur->root.reset(); return cur; } void erase() { if (lchild) lchild->root.reset(); if (rchild) rchild->root.reset(); root = merge(lchild, rchild); } static pointer_type merge(pointer_type x, pointer_type y) { if (!x) return y; if (!y) return x; if (comp(x->val, y->val) || x->val == y->val && comp(x->id, y->id)) std::swap(x, y); x->rchild = merge(x->rchild, y); if (!x->lchild || x->lchild->dist < x->rchild->dist) std::swap(x->lchild, x->rchild); if (x->lchild) x->lchild->root = x; if (x->rchild) x->rchild->root = x; x->dist = x->rchild ? x->rchild->dist + 1 : 0; return x; } }; int main() { std::ios::sync_with_stdio(false); cin.tie(nullptr); int n, m; cin >> n >> m; std::vector exists(n + 1, true); std::vector>::pointer_type> tr(n + 1); for (int i = 1, x; i <= n; i++) { cin >> x; tr[i] = std::make_shared(x, i); } while (m--) { int op; cin >> op; if (op == 1) { int x, y; cin >> x >> y; if (exists[x] && exists[y]) { auto fx = tr[x]->find_root(), fy = tr[y]->find_root(); if (fx != fy) { decltype(tr)::value_type::element_type::merge(fx, fy); } } } else { // op == 2 int x; cin >> x; if (exists[x]) { auto fx = tr[x]->find_root(); if (exists[fx->id]) { cout << fx->val << endl; fx->erase(); exists[fx->id] = false; } else { cout << -1 << endl; } } else { cout << -1 << endl; } } } return 0; }