結果

問題 No.399 動的な領主
コンテスト
ユーザー terasa
提出日時 2023-01-14 11:18:49
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 596 ms / 2,000 ms
コード長 4,361 bytes
コンパイル時間 262 ms
コンパイル使用メモリ 82,040 KB
実行使用メモリ 100,992 KB
最終ジャッジ日時 2024-12-25 17:20:09
合計ジャッジ時間 7,357 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge1
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ファイルパターン 結果
other AC * 19
権限があれば一括ダウンロードができます

ソースコード

diff # 

from typing import List, Tuple, Callable, TypeVar
import sys

input = sys.stdin.readline


class BIT:
    def __init__(self, N):
        self.N = N
        self.A = [0] * (N + 1)

    def build(self, A):
        """build BIT with given list"""
        for i, a in enumerate(A):
            self.A[i + 1] = a
        for i in range(1, self.N):
            if i + (i & -i) > self.N:
                continue
            self.A[i + (i & -i)] += self.A[i]

    def add(self, i, x):
        """add x to i-th element (0-indexed)"""
        # assert 0 <= i < self.N
        i += 1
        while i <= self.N:
            self.A[i] += x
            i += i & -i

    def sum(self, i):
        """return sum(A[:i])"""
        assert 0 <= i <= self.N
        s = 0
        while i > 0:
            s += self.A[i]
            i -= i & -i
        return s

    def range_sum(self, l, r):
        """return sum(A[l:r])"""
        return self.sum(r) - self.sum(l)


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)
bit = BIT(N)
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):
        bit.add(l, 1)
        bit.add(r, -1)
ans = 0
for i in range(N):
    cnt = bit.sum(i + 1)
    ans += (1 + cnt) * cnt // 2
print(ans)
0