#include using namespace std; using lint = long long int; using pint = pair; using plint = pair; struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((lint)(x).size()) #define POW2(n) (1LL << (n)) #define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) template void ndarray(vector &vec, int len) { vec.resize(len); } template void ndarray(vector &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); } template bool mmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; } template bool mmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; } template pair operator+(const pair &l, const pair &r) { return make_pair(l.first + r.first, l.second + r.second); } template pair operator-(const pair &l, const pair &r) { return make_pair(l.first - r.first, l.second - r.second); } template istream &operator>>(istream &is, vector &vec){ for (auto &v : vec) is >> v; return is; } ///// This part below is only for debug, not used ///// template ostream &operator<<(ostream &os, const vector &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; } template ostream &operator<<(ostream &os, const deque &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; } template ostream &operator<<(ostream &os, const set &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_set &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const multiset &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_multiset &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const pair &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; } template ostream &operator<<(ostream &os, const map &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_map &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } #define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl; ///// END ///// /* #include #include #include using namespace __gnu_pbds; // find_by_order(), order_of_key() template using pbds_set = tree, rb_tree_tag, tree_order_statistics_node_update>; template using pbds_map = tree, rb_tree_tag, tree_order_statistics_node_update>; */ class UndirectedWeightedTree { using T = lint; const int INVALID = -1; int V, lgV; int E; int root; vector> adj; // (nxt_vertex, edge_id) vector edges; vector weight; // w[edge_id] vector par; vector depth; vector acc_weight; // w_sum[vertex_id] public: UndirectedWeightedTree(int N = 0): V(N), E(0), adj(N) { lgV = 1; while (1 << lgV < V) lgV++; } void add_edge(int u, int v, T w) { adj[u].emplace_back(v, E); adj[v].emplace_back(u, E); edges.emplace_back(u, v); weight.emplace_back(w); E++; } void _fix_root_dfs(int now, int prv, int prv_edge_id) { par[now] = prv; if (prv_edge_id != INVALID) acc_weight[now] = acc_weight[prv] + weight[prv_edge_id]; for (auto nxt : adj[now]) if (nxt.first != prv) { depth[nxt.first] = depth[now] + 1; _fix_root_dfs(nxt.first, now, nxt.second); } } void fix_root(int r) { root = r; par.resize(V); depth.assign(V, 0); acc_weight.resize(V); _fix_root_dfs(root, INVALID, INVALID); } vector> doubling; void doubling_precalc() { doubling.assign(lgV, vector(V)); doubling[0] = par; REP(d, lgV - 1) REP(i, V) { if (doubling[d][i] == INVALID) doubling[d + 1][i] = INVALID; else doubling[d + 1][i] = doubling[d][doubling[d][i]]; } } int kth_parent(int x, int k) { REP(d, lgV) { if (x == INVALID) return INVALID; if (k & (1 << d)) x = doubling[d][x]; } return x; } int lowest_common_ancestor(int u, int v) { if (depth[u] > depth[v]) swap(u, v); v = kth_parent(v, depth[v] - depth[u]); if (u == v) return u; IREP(d, lgV) { if (doubling[d][u] != doubling[d][v]) u = doubling[d][u], v = doubling[d][v]; } return par[u]; } T path_length(int u, int v) { int r = lowest_common_ancestor(u, v); return acc_weight[u] + acc_weight[v] - acc_weight[r] * 2; } }; int main() { int N; cin >> N; UndirectedWeightedTree g(N); REP(_, N - 1) { int u, v, w; cin >> u >> v >> w; g.add_edge(u, v, w); } g.fix_root(0); g.doubling_precalc(); int Q; cin >> Q; REP(_, Q) { int x, y, z; cin >> x >> y >> z; int xy = g.lowest_common_ancestor(x, y); int xyz = g.lowest_common_ancestor(xy, z); if (xy != xyz) { cout << g.path_length(xy, z) + g.path_length(x, y) << endl; } else { int v = g.lowest_common_ancestor(x, z) + g.lowest_common_ancestor(y, z) - xy; cout << g.path_length(x, y) + g.path_length(z, v) << endl; } } }