結果
問題 |
No.2914 正閉路検出
|
ユーザー |
👑 |
提出日時 | 2024-10-04 23:13:23 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 159 ms / 2,000 ms |
コード長 | 3,677 bytes |
コンパイル時間 | 4,225 ms |
コンパイル使用メモリ | 261,732 KB |
最終ジャッジ日時 | 2025-02-24 15:36:45 |
ジャッジサーバーID (参考情報) |
judge1 / judge3 |
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ファイルパターン | 結果 |
---|---|
other | AC * 55 |
ソースコード
#include<bits/stdc++.h> #include<atcoder/all> #define rep(i,n) for(int i=0;i<n;i++) using namespace std; using namespace atcoder; typedef long long ll; typedef vector<int> vi; typedef vector<long long> vl; typedef vector<vector<int>> vvi; typedef vector<vector<long long>> vvl; typedef long double ld; typedef pair<int, int> P; template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;} template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;} template <int m> istream& operator>>(istream& is, static_modint<m>& a) {long long x; is >> x; a = x; return is;} template <int m> istream& operator>>(istream& is, dynamic_modint<m>& a) {long long x; is >> x; a = x; return is;} template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;} template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;} template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;} template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;} template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;} template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;} template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;} template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;} template<typename T> void chmin(T& a, T b){a = min(a, b);} template<typename T> void chmax(T& a, T b){a = max(a, b);} int main(){ int n, m; cin >> n >> m; vector<vector<tuple<int, int, long long>>> graph(n); vector<pair<int, int>> uv; rep(i, m){ int u, v; long long c; cin >> u >> v >> c; u--; v--; graph[u].emplace_back(i, v, c); graph[v].emplace_back(i, u, -c); uv.emplace_back(u, v); } vector<int> check(n); vector<long long> potential(n); vector<int> ans; deque<int> de; int ans_from; auto dfs = [&](auto self, int from, long long prev) -> void{ check[from] = 1; for(auto [idx, to, c] : graph[from]){ if(ans.size()) return; if(idx == prev) continue; if(check[to]){ if(potential[to] != potential[from] + c){ int pos = from; ans.push_back(idx); while(pos != to){ int idx = de.back(); de.pop_back(); if(uv[idx].first == pos) pos = uv[idx].second; else pos = uv[idx].first; ans.push_back(idx); } ans_from = to; if(potential[to] > potential[from] + c){ }else{ reverse(ans.begin(), ans.end()); } } }else{ potential[to] = potential[from] + c; de.push_back(idx); self(self, to, idx); if(ans.size() == int(0)) de.pop_back(); } } }; rep(i, n){ if(ans.size()) break; if(check[i]) continue; dfs(dfs, i, -1); } if(ans.size()){ cout << ans.size() << "\n"; cout << ans_from + 1 << "\n"; for(int& idx : ans) idx++; cout << ans; }else{ cout << "-1\n"; } return 0; }