結果
問題 | No.2301 Namorientation |
ユーザー |
|
提出日時 | 2023-05-12 22:13:19 |
言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 681 ms / 3,000 ms |
コード長 | 6,188 bytes |
コンパイル時間 | 14,856 ms |
コンパイル使用メモリ | 317,056 KB |
最終ジャッジ日時 | 2025-02-12 23:02:42 |
ジャッジサーバーID (参考情報) |
judge5 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 30 |
ソースコード
#line 1 "main.cpp"#ifdef LOCAL#include <local.hpp>#else#pragma GCC optimize("O3,unroll-loops")#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2")#include <bits/stdc++.h>#define debug(...) ((void)0)#define postprocess(...) ((void)0)#endif#line 1 "library/graph/shortest_path.hpp"#include <bits/stdc++.h>template <typename weight>struct shortest_path {const weight unreachable = std::numeric_limits<weight>::max();shortest_path() : _computed(false) {}shortest_path(const int& n, const int& m = 0) : _n(n), _computed(false) {if (m) _edges.reserve(m);}void set_number(const int& n, const int& m = 0) {_n = n;if (m) _edges.reserve(m);}void add_edge(const int& i, const int& j, const weight& w) {assert(0 <= i && i < _n);assert(0 <= j && j < _n);_edges.emplace_back(i, j, w);}void compute(const int& s) {_s = s;_computed = true;_adj.resize(_n);for (auto&& e : _edges) {auto [u, v, w] = e;_adj[u].emplace_back(v, w);}_dist.resize(_n);std::fill(_dist.begin(), _dist.end(), unreachable);_par.resize(_n);std::fill(_par.begin(), _par.end(), -1);// select best algorithmif (!std::is_integral<weight>::value) {_dijkstra(s);return;}for (auto&& [_, __, cost] : _edges) {if (cost >= 2) {_dijkstra(s);return;}}for (auto&& [_, __, cost] : _edges) {if (cost == 0) {_bfs01(s);return;}}_bfs(s);}int s() {assert(_computed);return _s;}std::vector<weight> dist() {assert(_computed);return _dist;}weight dist(const int& t) {assert(_computed);return _dist[t];}std::vector<int> path(int t) {assert(_computed);assert(0 <= t && t < _n);assert(_dist[t] != unreachable);std::vector<int> ret;while (t != _s) {ret.push_back(t);t = _par[t];}ret.push_back(_s);std::reverse(ret.begin(), ret.end());return ret;}private:// input valuesint _n;int _s;std::vector<std::tuple<int, int, weight>> _edges;// computed valuesbool _computed;std::vector<std::vector<std::pair<int, weight>>> _adj;std::vector<weight> _dist;std::vector<int> _par;void _bfs(const int& s) {std::queue<int> que;que.emplace(s);_dist[s] = 0;while (!que.empty()) {auto v = que.front();que.pop();for (auto&& [to, _] : _adj[v]) {if (_dist[to] == unreachable) {_dist[to] = _dist[v] + 1;_par[to] = v;que.emplace(to);}}}}void _bfs01(const int& s) {std::deque<int> que;_dist[s] = 0;que.emplace_back(s);while (!que.empty()) {auto v = que.front();que.pop_front();for (auto&& [to, cost] : _adj[v]) {weight d = _dist[v] + cost;if (d < _dist[to]) {_dist[to] = d;_par[to] = v;if (cost) {que.emplace_back(to);} else {que.emplace_front(to);}}}}}void _dijkstra(const int& s) {using que_class = std::pair<weight, int>;std::priority_queue<que_class, std::vector<que_class>, std::greater<que_class>> que;_dist[s] = 0;que.emplace(0, s);while (!que.empty()) {auto [d, v] = que.top();que.pop();if (_dist[v] != d) continue;for (auto&& [to, cost] : _adj[v]) {if (_dist[to] <= d + cost) continue;_dist[to] = d + cost;_par[to] = v;que.emplace(_dist[to], to);}}}};#line 12 "main.cpp"using namespace std;using ll = long long;using ld = long double;vector<vector<int>> adj;deque<int> cycle;vector<bool> visited;bool rec(int par = -1, int v = 0) {if (visited[v]) {while (cycle.front() != v) cycle.pop_front();return true;}visited[v] = true;cycle.push_back(v);for (auto&& u : adj[v]) {if (u == par) continue;if (rec(v, u)) return true;}cycle.pop_back();return false;}void solve([[maybe_unused]] int test) {int N;cin >> N;adj.resize(N);visited = vector<bool>(N, false);map<pair<int, int>, int> edge;shortest_path<int> sp(N);for (int i = 0; i < N; i++) {int A, B;cin >> A >> B;A--;B--;edge[{A, B}] = i;adj[A].push_back(B);adj[B].push_back(A);sp.add_edge(A, B, 1);sp.add_edge(B, A, 1);}rec();bool in_cycle[N];for (int i = 0; i < N; i++) {in_cycle[i] = false;}for (auto&& v : cycle) {in_cycle[v] = true;}bool ans[N];for (int i = 0; i < (int)cycle.size(); i++) {bool right = true;int a = cycle[i];int b = cycle[(i + 1) % (int)cycle.size()];if (!(a < b)) swap(a, b), right = false;assert(edge.count({a, b}));int e = edge[{a, b}];ans[e] = right;}sp.compute(cycle[0]);for (auto&& [E, e] : edge) {auto [a, b] = E;if (in_cycle[a] && in_cycle[b]) continue;ans[e] = sp.dist(a) > sp.dist(b);}for (int i = 0; i < N; i++) {cout << (ans[i] ? "->" : "<-") << endl;}}int main() {ios::sync_with_stdio(false);cin.tie(nullptr);int t = 1;// cin >> t;for (int i = 1; i <= t; i++) {solve(i);}postprocess();}