#define PROBLEM "https://yukicoder.me/problems/no/901" #include #include #include #include #include #include #include #include #include template class Graph { //using Node = int; //using Cost = long long; using Edge = std::pair; using Edges = std::vector; const int m_n; std::vector m_graph; public: Graph(int n) :m_n(n), m_graph(n) {} auto addEdge(const Node& f, const Node& t, const Cost& c = 1) { m_graph[f].emplace_back(t, c); } auto addEdgeUndirected(const Node& f, const Node& t, const Cost& c = 1) { addEdge(f, t, c); addEdge(t, f, c); } auto getEdges(const Node& from)const { class EdgesRange { const typename Edges::const_iterator b, e; public: EdgesRange(const Edges& edges) :b(edges.begin()), e(edges.end()) {} auto begin()const { return b; } auto end()const { return e; } }; return EdgesRange(m_graph[from]); } auto getEdges()const { std::deque> edges; for(Node from = 0; from < m_n; ++from) for(const auto& [to, c] : getEdges(from)) { edges.emplace_back(from, to, c); } return edges; } auto getEdgesExcludeCost()const { std::deque> edges; for(Node from = 0; from < m_n; ++from) for(const auto& [to, _] : getEdges(from)) { edges.emplace_back(from, to); } return edges; } auto reverse()const { auto rev = Graph(m_n); for(const auto& [from, to, c] : getEdges()) { rev.addEdge(to, from, c); } return rev; } auto size()const { return m_n; }; }; template class HeavyLightDecomposition { using GraphOrderd = std::unordered_map>; const Node m_n; const std::vector m_size; const GraphOrderd m_tree; const std::vector m_height; const std::vector> m_root_par; const std::vector m_ids; const std::vector m_order; const std::vector m_edge_ids; static auto constructGraph(const Graph& tree) { auto n = tree.size(); std::deque> order; std::vector used(n); std::stack> stk; stk.emplace(0, -1); used[0] = true; while(!stk.empty()) { auto [f, p] = stk.top(); order.emplace_front(f, p); stk.pop(); for(const auto& [t, _] : tree.getEdges(f)) { if(used[t]) { continue;; } used[t] = true; stk.emplace(t, f); } } std::vector size(n, 1); GraphOrderd hld_tree; for(const auto& [f, p] : order) { Node size_sum = 1; Node size_max = 0; std::deque to_list; for(const auto& [t, _] : tree.getEdges(f)) { if(t == p) { continue; } if(size[t] > size_max) { size_max = size[t]; to_list.emplace_back(t); } else { to_list.emplace_front(t); } size_sum += size[t]; } if(!to_list.empty()) { hld_tree.emplace(f, to_list); } size[f] = size_sum; } return hld_tree; } static auto constructSize(const Graph& tree) { auto n = tree.size(); std::deque> order; std::vector used(n); std::stack> stk; stk.emplace(0, -1); used[0] = true; while(!stk.empty()) { auto [f, p] = stk.top(); order.emplace_front(f, p); stk.pop(); for(const auto& [t, _] : tree.getEdges(f)) { if(used[t]) { continue;; } used[t] = true; stk.emplace(t, f); } } std::vector size(n, 1); for(const auto& [f, p] : order) { Node size_sum = 1; for(const auto& [t, _] : tree.getEdges(f)) { if(t == p) { continue; } size_sum += size[t]; } size[f] = size_sum; } return size; } static auto constructRootPar(Node n, const GraphOrderd& tree) { std::vector> root_par(n); std::stack> stk; stk.emplace(0, 0, -1); while(!stk.empty()) { auto [f, root, par] = stk.top(); stk.pop(); if(tree.find(f) == tree.end()) { root_par[f] = {root,par}; continue; } auto itr = tree.at(f).rbegin(); stk.emplace(*itr, root, par); root_par[f] = {root,par}; for(++itr; itr != tree.at(f).rend(); ++itr) { stk.emplace(*itr, *itr, f); } } return root_par; } static auto constructHeight(Node n, const GraphOrderd& tree) { std::vector height(n); std::queue q; q.emplace(0); while(!q.empty()) { auto f = q.front(); q.pop(); if(tree.find(f) == tree.end()) { continue; } for(const auto& t : tree.at(f)) { height[t] = height[f] + 1; q.emplace(t); } } return height; } auto constructIds() const { std::vector ids(m_n); Node val = 0; std::stack stk; stk.emplace(0); while(!stk.empty()) { auto f = stk.top(); stk.pop(); ids[f] = val; ++val; if(m_tree.find(f) == m_tree.end()) { continue; } for(const auto& t : m_tree.at(f)) { stk.emplace(t); } } return ids; } auto constructOrder()const { std::vector order(m_n); for(int i = 0; i < m_n; ++i) { order[m_ids[i]] = i; } return order; } /* * 辺をnodeとして拡張した場合の辺nodeだけIDを振る * (1) - (2) * (1) - (e) - (2) * [-1, -1, 0] */ auto constructEdgeIds() const { Node edge_size = (m_n >> 1); std::vector edge_ids(m_n, -1); Node val = 0; std::stack stk; stk.emplace(0); while(!stk.empty()) { auto f = stk.top(); stk.pop(); if(f > edge_size) { edge_ids[f] = val; ++val; } if(m_tree.find(f) == m_tree.end()) { continue; } for(const auto& t : m_tree.at(f)) { stk.emplace(t); } } return edge_ids; } public: HeavyLightDecomposition(const Graph& tree) : m_n(tree.size()), m_size(constructSize(tree)), m_tree(constructGraph(tree)), m_root_par(constructRootPar(m_n, m_tree)), m_height(constructHeight(m_n, m_tree)), m_ids(constructIds()), m_order(constructOrder()), m_edge_ids(constructEdgeIds()) { } auto getId(Node i)const { return m_ids[i]; } auto getEdgeId(Node i)const { return m_edge_ids[i]; } auto getOrder(Node i)const { return m_order[i]; } auto lca(Node f, Node t)const { do { auto [fr, fp] = m_root_par[f]; auto [tr, tp] = m_root_par[t]; if(fr == tr) { break; } auto fph = (fp > -1) ? m_height[fp] : -1; auto tph = (tp > -1) ? m_height[tp] : -1; if(fph < tph) { t = tp; } else { f = fp; } } while(true); return (m_height[f] < m_height[t]) ? f : t; } auto range(Node f, Node t)const { std::deque> ret; auto add = [&](Node f, Node t) { auto l = std::min(m_ids[f], m_ids[t]); auto r = std::max(m_ids[f], m_ids[t]); ret.emplace_back(l, r); }; do { auto [fr, fp] = m_root_par[f]; auto [tr, tp] = m_root_par[t]; if(fr == tr) { add(f, t); break; } auto fph = (fp > -1) ? m_height[fp] : -1; auto tph = (tp > -1) ? m_height[tp] : -1; if(fph < tph) { add(t, tr); t = tp; } else { add(f, fr); f = fp; } } while(true); return ret; } auto rangeEdge(Node f, Node t)const { Node edge_size = (m_n >> 1); std::deque> ret; auto add = [&](Node f, Node t) { auto l = std::min(m_ids[f], m_ids[t]); auto r = std::max(m_ids[f], m_ids[t]); if(m_order[l] <= edge_size) { ++l; } if(m_order[r] <= edge_size) { --r; } if(l > r) { return; } auto edge_l = m_edge_ids[m_order[l]]; auto edge_r = m_edge_ids[m_order[r]]; ret.emplace_back(edge_l, edge_r); }; do { auto [fr, fp] = m_root_par[f]; auto [tr, tp] = m_root_par[t]; if(fr == tr) { add(f, t); break; } auto fph = (fp > -1) ? m_height[fp] : -1; auto tph = (tp > -1) ? m_height[tp] : -1; if(fph < tph) { add(t, tr); t = tp; } else { add(f, fr); f = fp; } } while(true); return ret; } auto rangeSubTree(Node f)const { return std::pair{ m_ids[f], m_ids[f] + m_size[f] - 1 }; } }; template class AuxiliaryTree { // 定数倍高速化のため破壊的 std::vector compres_map; const std::vector depth_cost; const HeavyLightDecomposition hld; auto construct_depth(const Graph& tree)const { std::vector depth_cost(tree.size()); std::vector used(tree.size()); auto dfs = [&](auto&& self, Node from) -> void { used[from] = true; for(const auto& [to, c] : tree.getEdges(from)) if(!used[to]) { depth_cost[to] = depth_cost[from] + c; self(self, to); } }; dfs(dfs, 0); return depth_cost; } public: AuxiliaryTree(const Graph& tree) : compres_map(tree.size()), depth_cost(construct_depth(tree)), hld(tree) { } auto compression(const std::vector& nodes) { auto compare = [&](int a, int b) {return hld.getId(a) < hld.getId(b); }; // 元の頂点集合 auto nodes_set = std::set(nodes.begin(), nodes.end(), compare); auto nodes_set_with_lca = nodes_set; // pre orderでの全ての隣接nodeのLCAを求める for(auto itr = nodes_set_with_lca.begin(); std::next(itr) != nodes_set_with_lca.end(); ++itr) { nodes_set_with_lca.emplace(hld.lca(*itr, *std::next(itr))); } // 座標圧縮 int at_size = nodes_set_with_lca.size(); for(int i = 0; auto x : nodes_set_with_lca) { compres_map[x] = i; ++i; } // LCAを含めた全てのnodeで子孫関係を保って辺を張る std::stack stk; Graph auxiliary_tree(at_size); for(auto nd : nodes_set_with_lca) { while(!stk.empty() && hld.lca(stk.top(), nd) != stk.top()) { stk.pop(); } if(!stk.empty()) { auto f = compres_map[stk.top()]; auto t = compres_map[nd]; auto c = depth_cost[stk.top()] + depth_cost[nd] - depth_cost[hld.lca(stk.top(), nd)] * 2; auxiliary_tree.addEdgeUndirected(f, t, c); } stk.emplace(nd); } return auxiliary_tree; } }; int main() { std::cin.tie(0); std::ios::sync_with_stdio(0); int n; std::cin >> n; Graph tree(n); for(auto _ : std::views::iota(0, n - 1)) { int f, t, c; std::cin >> f >> t >> c; tree.addEdgeUndirected(f, t, c); } auto at = AuxiliaryTree(tree); int q; std::cin >> q; for([[maybe_unused]] auto _ : std::views::iota(0, q)) { int k; std::cin >> k; std::vector v(k); for(auto i : std::views::iota(0, k)) { std::cin >> v[i]; } auto comp_tree = at.compression(v); long long ans = 0; for(const auto& [f, t, c] : comp_tree.getEdges()) if(f < t) { ans += c; } std::cout << ans << "\n"; } }