結果
| 問題 | No.2337 Equidistant |
| ユーザー |
 hitonanode
|
| 提出日時 | 2023-06-02 21:42:06 |
| 言語 | C++23 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 14,430 bytes |
| コンパイル時間 | 2,065 ms |
| コンパイル使用メモリ | 189,576 KB |
| 実行使用メモリ | 24,256 KB |
| 最終ジャッジ日時 | 2024-06-08 22:35:28 |
| 合計ジャッジ時間 | 8,193 ms |
|
ジャッジサーバーID （参考情報） |
judge2 / judge5 |
（要ログイン）
テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 1 ms
5,248 KB |
| testcase_01 | WA | - |
| testcase_02 | WA | - |
| testcase_03 | WA | - |
| testcase_04 | WA | - |
| testcase_05 | WA | - |
| testcase_06 | WA | - |
| testcase_07 | WA | - |
| testcase_08 | WA | - |
| testcase_09 | WA | - |
| testcase_10 | WA | - |
| testcase_11 | WA | - |
| testcase_12 | WA | - |
| testcase_13 | WA | - |
| testcase_14 | WA | - |
| testcase_15 | WA | - |
| testcase_16 | WA | - |
| testcase_17 | WA | - |
| testcase_18 | WA | - |
| testcase_19 | WA | - |
| testcase_20 | WA | - |
| testcase_21 | WA | - |
| testcase_22 | AC | 169 ms
24,256 KB |
| testcase_23 | WA | - |
| testcase_24 | WA | - |
| testcase_25 | WA | - |
| testcase_26 | WA | - |
| testcase_27 | WA | - |
| testcase_28 | WA | - |
ソースコード
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T, typename V>
void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }
template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }
template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }
template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }
const std::vector<std::pair<int, int>> grid_dxs{{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <class T1, class T2> T1 floor_div(T1 num, T2 den) { return (num > 0 ? num / den : -((-num + den - 1) / den)); }
template <class T1, class T2> std::pair<T1, T2> operator+(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first + r.first, l.second + r.second); }
template <class T1, class T2> std::pair<T1, T2> operator-(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first - r.first, l.second - r.second); }
template <class T> std::vector<T> sort_unique(std::vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <class T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }
template <class T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }
template <class IStream, class T> IStream &operator>>(IStream &is, std::vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec);
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr);
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const pair<T, U> &pa);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp);
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp);
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
template <class... T> std::istream &operator>>(std::istream &is, std::tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa) { return os << '(' << pa.first << ',' << pa.second << ')'; }
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl
#define dbgif(cond, x) ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl : std::cerr)
#else
#define dbg(x) ((void)0)
#define dbgif(cond, x) ((void)0)
#endif
#include <algorithm>
#include <cassert>
#include <functional>
#include <queue>
#include <stack>
#include <utility>
#include <vector>
// Heavy-Light Decomposition of trees
// Based on http://beet-aizu.hatenablog.com/entry/2017/12/12/235950
struct HeavyLightDecomposition {
int V;
int k;
int nb_heavy_path;
std::vector<std::vector<int>> e;
std::vector<int> par; // par[i] = parent of vertex i (Default: -1)
std::vector<int> depth; // depth[i] = distance between root and vertex i
std::vector<int> subtree_sz; // subtree_sz[i] = size of subtree whose root is i
std::vector<int> heavy_child; // heavy_child[i] = child of vertex i on heavy path (Default: -1)
std::vector<int> tree_id; // tree_id[i] = id of tree vertex i belongs to
std::vector<int> aligned_id,
aligned_id_inv; // aligned_id[i] = aligned id for vertex i (consecutive on heavy edges)
std::vector<int> head; // head[i] = id of vertex on heavy path of vertex i, nearest to root
std::vector<int> head_ids; // consist of head vertex id's
std::vector<int> heavy_path_id; // heavy_path_id[i] = heavy_path_id for vertex [i]
HeavyLightDecomposition(int sz = 0)
: V(sz), k(0), nb_heavy_path(0), e(sz), par(sz), depth(sz), subtree_sz(sz), heavy_child(sz),
tree_id(sz, -1), aligned_id(sz), aligned_id_inv(sz), head(sz), heavy_path_id(sz, -1) {}
void add_edge(int u, int v) {
e[u].emplace_back(v);
e[v].emplace_back(u);
}
void _build_dfs(int root) {
std::stack<std::pair<int, int>> st;
par[root] = -1;
depth[root] = 0;
st.emplace(root, 0);
while (!st.empty()) {
int now = st.top().first;
int &i = st.top().second;
if (i < (int)e[now].size()) {
int nxt = e[now][i++];
if (nxt == par[now]) continue;
par[nxt] = now;
depth[nxt] = depth[now] + 1;
st.emplace(nxt, 0);
} else {
st.pop();
int max_sub_sz = 0;
subtree_sz[now] = 1;
heavy_child[now] = -1;
for (auto nxt : e[now]) {
if (nxt == par[now]) continue;
subtree_sz[now] += subtree_sz[nxt];
if (max_sub_sz < subtree_sz[nxt])
max_sub_sz = subtree_sz[nxt], heavy_child[now] = nxt;
}
}
}
}
void _build_bfs(int root, int tree_id_now) {
std::queue<int> q({root});
while (!q.empty()) {
int h = q.front();
q.pop();
head_ids.emplace_back(h);
for (int now = h; now != -1; now = heavy_child[now]) {
tree_id[now] = tree_id_now;
aligned_id[now] = k++;
aligned_id_inv[aligned_id[now]] = now;
heavy_path_id[now] = nb_heavy_path;
head[now] = h;
for (int nxt : e[now])
if (nxt != par[now] and nxt != heavy_child[now]) q.push(nxt);
}
nb_heavy_path++;
}
}
void build(std::vector<int> roots = {0}) {
int tree_id_now = 0;
for (auto r : roots) _build_dfs(r), _build_bfs(r, tree_id_now++);
}
template <class T> std::vector<T> segtree_rearrange(const std::vector<T> &data) const {
assert(int(data.size()) == V);
std::vector<T> ret;
ret.reserve(V);
for (int i = 0; i < V; i++) ret.emplace_back(data[aligned_id_inv[i]]);
return ret;
}
// query for vertices on path [u, v] (INCLUSIVE)
void
for_each_vertex(int u, int v, const std::function<void(int ancestor, int descendant)> &f) const {
while (true) {
if (aligned_id[u] > aligned_id[v]) std::swap(u, v);
f(std::max(aligned_id[head[v]], aligned_id[u]), aligned_id[v]);
if (head[u] == head[v]) break;
v = par[head[v]];
}
}
void for_each_vertex_noncommutative(
int from, int to, const std::function<void(int ancestor, int descendant)> &fup,
const std::function<void(int ancestor, int descendant)> &fdown) const {
int u = from, v = to;
const int lca = lowest_common_ancestor(u, v), dlca = depth[lca];
while (u >= 0 and depth[u] > dlca) {
const int p = (depth[head[u]] > dlca ? head[u] : lca);
fup(aligned_id[p] + (p == lca), aligned_id[u]), u = par[p];
}
static std::vector<std::pair<int, int>> lrs;
int sz = 0;
while (v >= 0 and depth[v] >= dlca) {
const int p = (depth[head[v]] >= dlca ? head[v] : lca);
if (int(lrs.size()) == sz) lrs.emplace_back(0, 0);
lrs.at(sz++) = {p, v}, v = par.at(p);
}
while (sz--) fdown(aligned_id[lrs.at(sz).first], aligned_id[lrs.at(sz).second]);
}
// query for edges on path [u, v]
void for_each_edge(int u, int v, const std::function<void(int, int)> &f) const {
while (true) {
if (aligned_id[u] > aligned_id[v]) std::swap(u, v);
if (head[u] != head[v]) {
f(aligned_id[head[v]], aligned_id[v]);
v = par[head[v]];
} else {
if (u != v) f(aligned_id[u] + 1, aligned_id[v]);
break;
}
}
}
// lowest_common_ancestor: O(log V)
int lowest_common_ancestor(int u, int v) const {
assert(tree_id[u] == tree_id[v] and tree_id[u] >= 0);
while (true) {
if (aligned_id[u] > aligned_id[v]) std::swap(u, v);
if (head[u] == head[v]) return u;
v = par[head[v]];
}
}
int distance(int u, int v) const {
assert(tree_id[u] == tree_id[v] and tree_id[u] >= 0);
return depth[u] + depth[v] - 2 * depth[lowest_common_ancestor(u, v)];
}
// Level ancestor, O(log V)
// if k-th parent is out of range, return -1
int kth_parent(int v, int k) const {
if (k < 0) return -1;
while (v >= 0) {
int h = head.at(v), len = depth.at(v) - depth.at(h);
if (k <= len) return aligned_id_inv.at(aligned_id.at(v) - k);
k -= len + 1, v = par.at(h);
}
return -1;
}
// Jump on tree, O(log V)
int s_to_t_by_k_steps(int s, int t, int k) const {
if (k < 0) return -1;
if (k == 0) return s;
int lca = lowest_common_ancestor(s, t);
if (k <= depth.at(s) - depth.at(lca)) return kth_parent(s, k);
return kth_parent(t, depth.at(s) + depth.at(t) - depth.at(lca) * 2 - k);
}
};
int main() {
int N, Q;
cin >> N >> Q;
HeavyLightDecomposition hld(N);
REP(e, N - 1) {
int a, b;
cin >> a >> b;
--a, --b;
hld.add_edge(a, b);
}
int root = 0;
hld.build({root});
while (Q--) {
int s, t;
cin >> s >> t;
--s, --t;
int d = hld.distance(s, t);
if (d % 2) {
cout << "0\n";
continue;
}
int r = hld.s_to_t_by_k_steps(s, t, d / 2);
int ret = N;
REP(_, 2) {
int u = hld.s_to_t_by_k_steps(r, s, 1);
if (hld.par.at(u) == r) {
ret -= hld.subtree_sz.at(u);
} else {
assert(hld.par.at(r) == u);
ret -= hld.subtree_sz.at(r);
}
swap(s, t);
}
cout << ret << '\n';
}
}