結果
| 問題 | No.2337 Equidistant |
| ユーザー |
 kaikey
|
| 提出日時 | 2023-06-02 22:03:05 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 6,778 bytes |
| コンパイル時間 | 2,706 ms |
| コンパイル使用メモリ | 217,368 KB |
| 最終ジャッジ日時 | 2025-02-13 18:24:28 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge5 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 1 |
| other | AC * 1 WA * 27 |
ソースコード
#include "bits/stdc++.h"#include <random>#include <chrono>#define ALL(x) (x).begin(), (x).end()#define RALL(x) (x).rbegin(), (x).rend()#define SZ(x) ((lint)(x).size())#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;++i)#define IFOR(i, begin, end) for(lint 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)#define endk '\n'using namespace std; typedef unsigned long long _ulong; typedef int lint; typedef double ld; typedef pair<lint, lint> plint; typedef pair<ld, ld> pld;struct fast_ios { fast_ios() { cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(30); }; } fast_ios_;template<class T> auto add = [](T a, T b) -> T { return a + b; };template<class T> auto mul = [](T a, T b) -> T { return a * b; };template<class T> auto f_max = [](T a, T b) -> T { return max(a, b); };template<class T> auto f_min = [](T a, T b) -> T { return min(a, b); };template<class T> using V = vector<T>;using Vl = V<lint>; using VVl = V<Vl>; using VVVl = V<V<Vl>>;template< typename T > ostream& operator<<(ostream& os, const vector< T >& v) {for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : "");return os;}template< typename T >istream& operator>>(istream& is, vector< T >& v) {for (T& in : v) is >> in;return is;}template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }template <class T>T div_floor(T a, T b) {if (b < 0) a *= -1, b *= -1;return a >= 0 ? a / b : (a + 1) / b - 1;}template <class T>T div_ceil(T a, T b) {if (b < 0) a *= -1, b *= -1;return a > 0 ? (a - 1) / b + 1 : a / b;}template <class F> struct rec {F f;rec(F&& f_) : f(std::forward<F>(f_)) {}template <class... Args> auto operator()(Args &&... args) const {return f(*this, std::forward<Args>(args)...);}};lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); }lint digit(lint a) { return (lint)log10(a); }lint e_dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); }lint m_dist(plint a, plint b) { return abs(a.first - b.first) + abs(a.second - b.second); }bool check_overflow(lint a, lint b, lint limit) { if (b == 0) return false; return a > limit / b; } // a * b > c => truevoid Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); }const long long MOD1000000007 = 1000000007, MOD998244353 = 998244353, INF = 1e18;lint dx[8] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[8] = { 1, 0, -1, 0, -1, -1, 1, 1 };bool YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; return flag; } bool yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; return flag; }struct Edge {lint from, to;lint cost;Edge() {}Edge(lint u, lint v, lint c) {cost = c;from = u;to = v;}bool operator<(const Edge& e) const {return cost < e.cost;}};struct WeightedEdge {lint to;lint cost;WeightedEdge(lint v, lint c) {to = v;cost = c;}bool operator<(const WeightedEdge& e) const {return cost < e.cost;}};using WeightedGraph = V<V<WeightedEdge>>;typedef pair<plint, lint> tlint;typedef pair<ld, ld> pld;typedef pair<plint, plint> qlint;typedef pair<lint, string> vstr;typedef pair<string, string> pstr;typedef pair<set<lint>, set<lint>> pset;template< typename G >struct DoublingLowestCommonAncestor {int LOG = 2;vector< int > dep;const G& g;vector< vector< int > > table;DoublingLowestCommonAncestor(const G& g) : g(g), dep(g.size()) {int curr = 1;while (curr < g.size()) {curr *= 2;LOG++;}table.assign(LOG, vector< int >(g.size(), 0));}void dfs(int idx, int par, int d) {table[0][idx] = par;dep[idx] = d;for (auto& to : g[idx]) {if (to != par) dfs(to, idx, d + 1);}}void build() {dfs(0, -1, 0);for (int k = 0; k + 1 < LOG; k++) {for (int i = 0; i < table[k].size(); i++) {if (table[k][i] == -1) table[k + 1][i] = -1;else table[k + 1][i] = table[k][table[k][i]];}}}int query(int u, int v) {if (dep[u] > dep[v]) swap(u, v);for (int i = LOG - 1; i >= 0; i--) {if (((dep[v] - dep[u]) >> i) & 1) v = table[i][v];}if (u == v) return u;for (int i = LOG - 1; i >= 0; i--) {if (table[i][u] != table[i][v]) {u = table[i][u];v = table[i][v];}}return table[0][u];}int _query(int k, int64_t t){for (int i = LOG - 1; i >= 0; i--) {if ((t >> i) & 1) k = table[i][k];if (k == -1) return 0;}return k;}};struct Rerooting {VVl dp;VVl to;Rerooting(lint sz) {dp.resize(sz);to.resize(sz);}void add_edge(int u, int v) {to[u].push_back(v);to[v].push_back(u);}void build() {dfs(0);dfs2(0, 0);}lint dfs(lint curr, lint prv = -1) {lint sum = 1;lint deg = SZ(to[curr]);dp[curr] = Vl(deg, 0);REP(i, deg) {lint nxt = to[curr][i];if (nxt == prv) continue;dp[curr][i] = dfs(nxt, curr);sum += dp[curr][i];}return sum;}void dfs2(lint curr, lint score, lint prv = -1) {lint deg = SZ(to[curr]);REP(i, deg) {if (to[curr][i] == prv) dp[curr][i] = score;}Vl dp_l(deg + 1, 0), dp_r(deg + 1, 0);REP(i, deg) {dp_l[i + 1] = dp_l[i] + dp[curr][i];}IREP(i, deg) {dp_r[i] = dp_r[i + 1] + dp[curr][i];}REP(i, deg) {lint nxt = to[curr][i];if (nxt == prv) continue;dfs2(nxt, dp_l[i] + dp_r[i + 1] + 1, curr);}}};int main() {lint N, Q;cin >> N >> Q;VVl to(N);Rerooting dp(N);V<map<lint, lint>> fdx(N);REP(i, N - 1) {lint u, v;cin >> u >> v; u--; v--;to[u].push_back(v);to[v].push_back(u);fdx[u][v] = SZ(dp.dp[u]);fdx[v][u] = SZ(dp.dp[v]);dp.add_edge(u, v);}DoublingLowestCommonAncestor lca(to);lca.build();dp.build();auto getd = [&](lint u, lint v) {return lca.dep[u] + lca.dep[v] - 2 * lca.dep[lca.query(u, v)];};REP(i, Q) {lint s, t;cin >> s >> t; s--; t--;lint d = getd(s, t);if (d % 2 == 1) {cout << 0 << endk;continue;}d /= 2;lint mid = -1, _lca = lca.query(s, t);lint sl = lca._query(s, d), tl = lca._query(t, d);if (sl != _lca) mid = sl;if (tl != _lca) mid = tl;lint sn, tn;if (sl == tl) {sn = lca._query(s, d - 1);tn = lca._query(t, d - 1);mid = _lca;}else {if (sl != _lca) {sn = lca._query(s, d - 1);tn = lca._query(s, d + 1);}else {tn = lca._query(t, d - 1);sn = lca._query(t, d + 1);}}lint ans = N;ans -= dp.dp[mid][fdx[mid][sn]];ans -= dp.dp[mid][fdx[mid][tn]];cout << ans << endk;}}