結果
問題 | No.2337 Equidistant |
ユーザー |
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提出日時 | 2023-06-02 21:50:36 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
WA
|
実行時間 | - |
コード長 | 7,692 bytes |
コンパイル時間 | 3,275 ms |
コンパイル使用メモリ | 187,624 KB |
最終ジャッジ日時 | 2025-02-13 18:03:50 |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 1 |
other | AC * 3 WA * 25 |
ソースコード
#include <algorithm>#include <bitset>#include <cassert>#include <cmath>#include <cstdio>#include <fstream>#include <functional>#include <iomanip>#include <iostream>#include <iterator>#include <map>#include <numeric>#include <queue>#include <set>#include <sstream>#include <stack>#include <unordered_set>using namespace std;#if __has_include(<atcoder/all>)#include <atcoder/all>#endif#define GET_MACRO(_1, _2, _3, NAME, ...) NAME#define _rep(i, n) _rep2(i, 0, n)#define _rep2(i, a, b) for (int i = (int)(a); i < (int)(b); i++)#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)#define all(x) (x).begin(), (x).end()#define rall(x) (x).rbegin(), (x).rend()#define UNIQUE(x) \std::sort((x).begin(), (x).end()); \(x).erase(std::unique((x).begin(), (x).end()), (x).end())using i64 = long long;template <class T, class U>bool chmin(T& a, const U& b) {return (b < a) ? (a = b, true) : false;}template <class T, class U>bool chmax(T& a, const U& b) {return (b > a) ? (a = b, true) : false;}inline void YesNo(bool f = 0, string yes = "Yes", string no = "No") {std::cout << (f ? yes : no) << "\n";}namespace io {template <typename T>istream& operator>>(istream& i, vector<T>& v) {rep(j, v.size()) i >> v[j];return i;}template <typename T>string join(vector<T>& v) {stringstream s;rep(i, v.size()) s << ' ' << v[i];return s.str().substr(1);}template <typename T>ostream& operator<<(ostream& o, vector<T>& v) {if (v.size()) o << join(v);return o;}template <typename T>string join(vector<vector<T>>& vv) {string s = "\n";rep(i, vv.size()) s += join(vv[i]) + "\n";return s;}template <typename T>ostream& operator<<(ostream& o, vector<vector<T>>& vv) {if (vv.size()) o << join(vv);return o;}template <class T, class U>istream& operator>>(istream& i, pair<T, U>& p) {i >> p.first >> p.second;return i;}template <class T, class U>ostream& operator<<(ostream& o, pair<T, U>& p) {o << p.first << " " << p.second;return o;}void print() { cout << "\n"; }template <class Head, class... Tail>void print(Head&& head, Tail&&... tail) {cout << head;if (sizeof...(tail)) cout << ' ';print(std::forward<Tail>(tail)...);}void in() {}template <class Head, class... Tail>void in(Head&& head, Tail&&... tail) {cin >> head;in(std::forward<Tail>(tail)...);}} // namespace iousing namespace io;namespace useful {long long modpow(long long a, long long b, long long mod) {long long res = 1;while (b) {if (b & 1) res *= a, res %= mod;a *= a;a %= mod;b >>= 1;}return res;}bool is_pow2(long long x) { return x > 0 && (x & (x - 1)) == 0; }template <class T>void rearrange(vector<T>& a, vector<int>& p) {vector<T> b = a;for (int i = 0; i < int(a.size()); i++) {a[i] = b[p[i]];}return;}template <class T>vector<pair<int, int>> rle_sequence(T& a) {vector<pair<int, int>> res;int n = a.size();if (n == 1) return vector<pair<int, int>>{{a[0], 1}};int l = 1;rep(i, n - 1) {if (a[i] == a[i + 1])l++;else {res.emplace_back(a[i], l);l = 1;}}res.emplace_back(a.back(), l);return res;}vector<pair<char, int>> rle_string(string a) {vector<pair<char, int>> res;int n = a.size();if (n == 1) return vector<pair<char, int>>{{a[0], 1}};int l = 1;rep(i, n - 1) {if (a[i] == a[i + 1])l++;else {res.emplace_back(a[i], l);l = 1;}}res.emplace_back(a.back(), l);return res;}vector<int> linear_sieve(int n) {vector<int> primes;vector<int> res(n + 1);iota(all(res), 0);for (int i = 2; i <= n; i++) {if (res[i] == i) primes.emplace_back(i);for (auto j : primes) {if (j * i > n) break;res[j * i] = j;}}return res;// return primes;}template <class T>vector<long long> dijkstra(vector<vector<pair<int, T>>>& graph, int start) {int n = graph.size();vector<long long> res(n, 2e18);res[start] = 0;priority_queue<pair<long long, int>, vector<pair<long long, int>>,greater<pair<long long, int>>>que;que.push({0, start});while (!que.empty()) {auto [c, v] = que.top();que.pop();if (res[v] < c) continue;for (auto [nxt, cost] : graph[v]) {auto x = c + cost;if (x < res[nxt]) {res[nxt] = x;que.push({x, nxt});}}}return res;}} // namespace usefulusing namespace useful;struct LowestCommonAncestor {using G = vector<vector<int>>;private:const G& graph;const int n;vector<int> depth;vector<vector<int>> table;const int log = 20;inline void bfs(int st) {depth[st] = 0;queue<int> que;que.emplace(st);while (!que.empty()) {auto now = que.front();que.pop();for (auto e : graph[now]) {if (depth[e] != -1) continue;depth[e] = depth[now] + 1;table[e][0] = now;que.emplace(e);}}}public:LowestCommonAncestor(const G& g, int root = 0) : graph(g), n(g.size()) {depth = vector<int>(n, -1);table = vector(n, vector<int>(log, -1));bfs(root);for (int k = 0; k < log - 1; k++) {for (int i = 0; i < n; i++) {if (table[i][k] == -1)table[i][k + 1] = -1;elsetable[i][k + 1] = table[table[i][k]][k];}}}int LCA(int a, int b) {if (depth[a] < depth[b]) swap(a, b);for (int i = log - 1; i >= 0; i--) {if ((depth[a] - depth[b]) >> i & 1) a = table[a][i];}if (a == b) return a;for (int i = log - 1; i >= 0; i--) {if (table[a][i] != table[b][i]) {a = table[a][i];b = table[b][i];}}return table[a][0];}int distance(int u, int v) {return depth[u] + depth[v] - 2 * depth[LCA(u, v)];}int la(int x, int k) {for (int i = 0; i < log; i++) {if (k >> i & 1) {x = table[x][i];}}return x;}};vector<vector<int>> e;int c_sz[200010];int dfs(int now, int p) {c_sz[now] = 1;for (auto j : e[now]) {if (j == p) continue;c_sz[now] += dfs(j, now);}return c_sz[now];}int main() {cin.tie(nullptr);ios::sync_with_stdio(false);int n, q;in(n, q);e.resize(n);rep(i, n - 1) {int a, b;in(a, b);a--, b--;e[a].emplace_back(b);e[b].emplace_back(a);}LowestCommonAncestor lca(e);while (q--) {int s, t;in(s, t);s--, t--;auto l = lca.LCA(s, t);auto ds = lca.distance(l, s);auto dt = lca.distance(l, t);if ((ds & 1) != (dt & 1)) {print(0);continue;}if (ds < dt) {swap(s, t);swap(ds, dt);}int b = (ds - dt) / 2;int dcenter = ds - b;int center = lca.la(s, dcenter);int cen_to_s = lca.la(s, dcenter - 1);print(c_sz[center] + 1 - c_sz[cen_to_s]);}}