#include namespace { #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wunused-function" #include #pragma GCC diagnostic pop using namespace std; using namespace atcoder; #define rep(i,n) for(int i = 0; i < (int)(n); i++) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) template bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; } using ll = long long; using P = pair; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; struct HLD { const vector>& to; int root, n; vector sz, parent, depth, idx, ridx, head, inv; HLD(const vector>& to, int root=0) : to(to), root(root), n(to.size()), sz(n), parent(n), depth(n), idx(n), ridx(n), head(n), inv(n) { init_tree_data(root, -1, 0); int nxt = 0; assign_idx(root, root, nxt); } void init_tree_data(int u, int p, int d) { parent[u] = p; depth[u] = d; int s = 1; for (int v: to[u]) if (v != p) { init_tree_data(v, u, d+1); s += sz[v]; } sz[u] = s; } void assign_idx(int u, int h, int& nxt, int p=-1) { head[u] = h; idx[u] = nxt; inv[nxt] = u; nxt++; int heaviest = -1; int mxweight = 0; for (int v: to[u]) if (v != p) { if (sz[v] > mxweight) { heaviest = v; mxweight = sz[v]; } } if (heaviest != -1) { assign_idx(heaviest, h, nxt, u); for (int v: to[u]) if (v != p && v != heaviest) { assign_idx(v, v, nxt, u); } } ridx[u] = nxt; } int lca(int u, int v) { while (head[u] != head[v]) { if (depth[head[u]] > depth[head[v]]) { u = parent[head[u]]; } else { v = parent[head[v]]; } } return depth[u] < depth[v] ? u : v; } // returns reference to tuple of (path fragments from x upto lca (excluding lca), those from y, lca) // storage of retval is reused to avoid creating short vectors on each query tuple>, vector>, int> paths_res; auto& paths(int x, int y) { auto& [x_paths, y_paths, lca] = paths_res; x_paths.clear(); y_paths.clear(); while (head[x] != head[y]) { int hx = head[x], hy = head[y]; if (depth[hx] > depth[hy]) { x_paths.emplace_back(x, hx); x = parent[hx]; } else { y_paths.emplace_back(y, hy); y = parent[hy]; } } if (depth[x] > depth[y]) { x_paths.emplace_back(x, inv[idx[y] + 1]); x = y; } else if (depth[x] < depth[y]) { y_paths.emplace_back(y, inv[idx[x] + 1]); y = x; } lca = x; return paths_res; } int dist(int u, int v) { int w = lca(u, v); return depth[u] + depth[v] - 2 * depth[w]; } template int max_ancestor(int v, F f) { if (!f(v)) return -1; int hv = head[v]; int p = parent[hv]; while (p != -1 && f(p)) { v = p; hv = head[v]; p = parent[hv]; } int il = idx[hv] - 1, ir = idx[v]; while (ir - il > 1) { int ic = (il + ir) / 2; (f(inv[ic]) ? ir : il) = ic; } return inv[ir]; } int ascend(int v, int k) { assert(depth[v] >= k); int td = depth[v] - k; int hv = head[v]; while (depth[hv] > td) { v = parent[hv]; hv = head[v]; } int rest = depth[v] - td; return inv[idx[v] - rest]; } }; struct S { ll w, wc, wc2; }; S op(S x, S y) { return S{x.w + y.w, x.wc + y.wc, x.wc2 + y.wc2}; } S e() { return S{0, 0, 0}; } int composition(int f, int g) { return f + g; } int id() { return 0; } S mapping(int f, S x) { // sum w(c+f)(c+f-1)/2 = sum wc(c-1)/2 + f sum wc + f(f-1)/2 * sum w // sum w(c+f) = sum wc + f sum w return S{x.w, x.wc + f * x.w, x.wc2 + f * x.wc + (ll)f * (f-1) / 2 * x.w}; } } int main() { ios::sync_with_stdio(false); cin.tie(0); int n, q; cin >> n >> q; VVI to(2 * n); rep(_, n - 1) { int a, b; cin >> a >> b; a--, b--; to[a].emplace_back(b); to[b].emplace_back(a); } rep(i, n) { to[i].emplace_back(i + n); to[i + n].emplace_back(i); } n *= 2; HLD hld(to); vector init_vec(n); for(int i = 1; i < n; i++) init_vec[hld.idx[i]].w = i - hld.parent[i]; lazy_segtree seg_descend(init_vec); for(int i = 1; i < n; i++) init_vec[i].w = -init_vec[i].w; lazy_segtree seg_ascend(init_vec); fenwick_tree ft(n); while(q--) { int u, r, v; cin >> u >> r >> v; u--, r--, v--; if (r == v) r = v + n / 2; int add = ft.sum(hld.idx[u], hld.idx[u] + 1) == 0 ? 1 : -1; ft.add(hld.idx[u], add); seg_ascend.apply(0, n, add); for(auto [x, y]: get<0>(hld.paths(u, 0))) { int ix = hld.idx[x], iy = hld.idx[y]; seg_ascend.apply(iy, ix + 1, -add); seg_descend.apply(iy, ix + 1, add); } ll ans = 0; if (hld.lca(r, v) == v) { int t = hld.ascend(r, hld.depth[r] - hld.depth[v] - 1); int cnt = ft.sum(0, hld.idx[t]) + ft.sum(hld.ridx[t], n); ans += (ll)(v + 1) * cnt * (cnt - 1) / 2; ans += seg_descend.prod(0, n).wc2 - seg_descend.prod(hld.idx[t], hld.ridx[t]).wc2; for(auto [x, y]: get<0>(hld.paths(v, 0))) { int ix = hld.idx[x], iy = hld.idx[y]; ans -= seg_descend.prod(iy, ix + 1).wc2; ans += seg_ascend.prod(iy, ix + 1).wc2; } } else { int cnt = ft.sum(hld.idx[v], hld.ridx[v]); ans += (ll)(v + 1) * cnt * (cnt - 1) / 2; ans += seg_descend.prod(hld.idx[v] + 1, hld.ridx[v]).wc2; } cout << ans << '\n'; } }