from typing import List, Tuple, Callable, TypeVar import sys input = sys.stdin.readline T = TypeVar('T') class DualSegTree: # reference: https://hackmd.io/@tatyam-prime/DualSegmentTree def __init__(self, N: int, f: Callable[[T, T], T], e: T): """双対セグメント木 Args: N (int): 配列の長さ f (Callable[[T, T], T]): 作用させる関数 e (T): 単位元 Note: 値に作用を適応させる操作(遅延セグメント木のmappingに相当)と、 作用を合成する操作(遅延セグメント木のcompositionに相当)が、 同一の操作として記述できることが必要 例) 区間加算・区間代入・区間chmin等 """ self.N = N self.f = f self.e = e self.K = (self.N - 1).bit_length() self.size = 1 << self.K self.lazy = [e] * (self.size << 1) def build(self, A: List[T]) -> None: for i in range(self.N): self.lazy[self.size + i] = A[i] def _propagate_at(self, i: int) -> None: if self.lazy[i] == self.e: return self.lazy[i << 1] = self.f(self.lazy[i << 1], self.lazy[i]) self.lazy[i << 1 | 1] = self.f(self.lazy[i << 1 | 1], self.lazy[i]) self.lazy[i] = self.e def _propagate_above(self, i: int) -> None: H = i.bit_length() - 1 for h in range(H, 0, -1): self._propagate_at(i >> h) def get(self, i: int) -> T: i += self.size self._propagate_above(i) return self.lazy[i] def set(self, i: int, a: T) -> None: i += self.size self._propagate_above(i) self.lazy[i] = a def query(self, l: int, r: int, a: T) -> None: assert 0 <= l and l <= r and r <= self.N l += self.size r += self.size self._propagate_above(l // (l & -l)) self._propagate_above(r // (r & -r) - 1) while l < r: if l & 1: self.lazy[l] = self.f(self.lazy[l], a) l += 1 if r & 1: r -= 1 self.lazy[r] = self.f(self.lazy[r], a) l >>= 1 r >>= 1 class HLD: # reference: https://codeforces.com/blog/entry/53170 def __init__(self, N, E, root: int = 0): self.N = N self.E = E self.root = root self.D = [0] * self.N self.par = [-1] * self.N self.sz = [0] * self.N self.top = [0] * self.N self.ord = [None] * self.N self._dfs_sz() self._dfs_hld() def path_query_range(self, u: int, v: int, is_edge_query: bool = False) -> List[Tuple[int, int]]: """return list of [l, r) ranges that cover u-v path""" ret = [] while True: if self.ord[u] > self.ord[v]: u, v = v, u if self.top[u] == self.top[v]: ret.append((self.ord[u] + is_edge_query, self.ord[v] + 1)) return ret ret.append((self.ord[self.top[v]], self.ord[v] + 1)) v = self.par[self.top[v]] def subtree_query_range(self, v: int) -> Tuple[int, int]: """return [l, r) range that cover vertices of subtree v""" return (self.ord[v], self.ord[v] + self.sz[v]) def lca(self, u, v): while True: if self.ord[u] > self.ord[v]: u, v = v, u if self.top[u] == self.top[v]: return u v = self.par[self.top[v]] def _dfs_sz(self): stack = [(self.root, -1)] while stack: v, p = stack.pop() if v < 0: v = ~v self.sz[v] = 1 for i, dst in enumerate(self.E[v]): if dst == p: continue self.sz[v] += self.sz[dst] # v -> E[v][0] will be heavy path if self.sz[E[v][0]] < self.sz[dst]: self.E[v][0], self.E[v][i] = self.E[v][i], self.E[v][0] else: if ~p: self.D[v] = self.D[p] + 1 self.par[v] = p # avoid first element of E[v] is parent of vertex v if v has some children if len(self.E[v]) >= 2 and self.E[v][0] == p: self.E[v][0], self.E[v][1] = self.E[v][1], self.E[v][0] stack.append((~v, p)) for dst in self.E[v]: if dst == p: continue stack.append((dst, v)) def _dfs_hld(self): stack = [(self.root, -1)] cnt = 0 while stack: v, p = stack.pop() self.ord[v] = cnt cnt += 1 heavy_path_idx = len(self.E[v]) - 1 for i, dst in enumerate(self.E[v][::-1]): if dst == p: continue # top[dst] is top[v] if v -> dst is heavy path otherwise dst itself self.top[dst] = self.top[v] if i == heavy_path_idx else dst stack.append((dst, v)) N = int(input()) E = [[] for _ in range(N)] for _ in range(N - 1): u, v = map(int, input().split()) u -= 1 v -= 1 E[u].append(v) E[v].append(u) solver = HLD(N, E) dst = DualSegTree(N, lambda a, b: a + b, 0) Q = int(input()) for _ in range(Q): a, b = map(int, input().split()) a -= 1 b -= 1 for l, r in solver.path_query_range(a, b): dst.query(l, r, 1) ans = 0 for i in range(N): cnt = dst.get(i) ans += (1 + cnt) * cnt // 2 print(ans)