#include #define rep(i,n) for (int i = 0; i < (n); ++i) #define all(x) (x).begin(),(x).end() using namespace std; using ll = long long; template void chmin(T &a, const T &b) noexcept { if (b < a) a = b; } template void chmax(T &a, const T &b) noexcept { if (a < b) a = b; } template struct LowestCommonAncestor { private: vector > par; vector dist; //from root vector weight; //from root vector > max_w; const vector > > &G; void dfs_(int v, int p, int d, T w) { par[0][v] = p; dist[v] = d; weight[v] = w; for (auto to : G[v]) { if (to.first == p) continue; dfs_(to.first, v, d+1, w+to.second); max_w[0][to.first] = to.second; } } int query(int u,int v) { assert(u < (int)dist.size()); assert(v < (int)dist.size()); if (dist[u] > dist[v]) swap(u,v); int k = par.size(); for (int i = 0; i < k; ++i) { //LCAまでの距離を揃える if (((dist[v]-dist[u])>>i) & 1) v = par[i][v]; } if (u == v) return u; for (int i = k-1; i >= 0; --i) { if (par[i][u] == par[i][v]) continue; u = par[i][u]; v = par[i][v]; } return par[0][u]; } public: LowestCommonAncestor(const vector > > &G, int root = 0):G(G){ int n = G.size(), k = 1; while ((1<(n,-1)); dist.assign(n,-1); weight.assign(n,-1); max_w.assign(k, vector(n,-1)); dfs_(root, -1, 0, 0); for (int i = 0; i < k-1; ++i) { for (int v = 0; v < n; ++v) { if (par[i][v] < 0) par[i+1][v] = -1; else { par[i+1][v] = par[i][par[i][v]]; max_w[i+1][v] = max(max_w[i][v], max_w[i][par[i][v]]); } } } } T get_max_w(int u, int v) { int x = query(u,v), k = par.size(); T res = 0; for (int i = 0; i < k; ++i) { //LCAまで移動 if (((dist[x]-dist[u])>>i) & 1) { chmax(res, max_w[i][u]); u = par[i][u]; } } for (int i = 0; i < k; ++i) { if (((dist[x]-dist[v])>>i) & 1) { chmax(res, max_w[i][v]); v = par[i][v]; } } return res; } int operator()(int u,int v){ return query(u,v);} int get_dist(int u, int v){ return dist[u] + dist[v] - 2*dist[query(u,v)];} T get_weight(int u, int v){ return weight[u] + weight[v] - 2*weight[query(u,v)];} bool is_on_path(int u, int v, int a){ return get_dist(u,a)+get_dist(a,v)==get_dist(u,v);} }; int main() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(15); int n; cin >> n; using P = pair; vector > G(n); rep(i,n-1) { int u,v; ll w; cin >> u >> v >> w; G[u].emplace_back(P(v,w)); G[v].emplace_back(P(u,w)); } LowestCommonAncestor LCA(G, 0); int q; cin >> q; rep(i_,q) { int x,y,z; cin >> x >> y >> z; ll res = LCA.get_weight(x,y) + LCA.get_weight(y,z) + LCA.get_weight(z,x); res /= 2; cout << res << "\n"; } return 0; }