| #include <bits/stdc++.h> |
| using namespace std; |
|
|
| int main() { |
| ios::sync_with_stdio(false); |
| cin.tie(0); |
| int n, m; |
| cin >> n >> m; |
| vector<int> a(10); |
| for (int i = 0; i < 10; i++) cin >> a[i]; |
| vector<vector<int>> adj(n + 1); |
| vector<int> indeg(n + 1, 0); |
| for (int i = 0; i < m; i++) { |
| int u, v; |
| cin >> u >> v; |
| adj[u].push_back(v); |
| indeg[v]++; |
| } |
| vector<pair<int, int>> candidates; |
| for (int i = 1; i <= n; i++) { |
| candidates.emplace_back(indeg[i], i); |
| } |
| sort(candidates.begin(), candidates.end()); |
| vector<int> path; |
| path.reserve(n); |
| vector<int> vis_time(n + 1, 0); |
| int timestamp = 0; |
| vector<int> best_path; |
| int best_k = 0; |
| auto dfs = [&](auto&& self, int u, int cur_time) -> bool { |
| path.push_back(u); |
| vis_time[u] = cur_time; |
| bool res = false; |
| if (path.size() == static_cast<size_t>(n)) { |
| res = true; |
| } else { |
| for (int v : adj[u]) { |
| if (vis_time[v] != cur_time) { |
| if (self(self, v, cur_time)) { |
| res = true; |
| break; |
| } |
| } |
| } |
| } |
| if (!res) { |
| if (static_cast<int>(path.size()) > best_k) { |
| best_k = path.size(); |
| best_path = path; |
| } |
| path.pop_back(); |
| vis_time[u] = 0; |
| return false; |
| } else { |
| return true; |
| } |
| }; |
| bool found_ham = false; |
| for (auto& p : candidates) { |
| int start = p.second; |
| timestamp++; |
| path.clear(); |
| if (dfs(dfs, start, timestamp)) { |
| best_path = path; |
| best_k = n; |
| found_ham = true; |
| break; |
| } |
| } |
| if (best_k == 0) { |
| cout << 1 << '\n' << 1 << '\n'; |
| } else { |
| cout << best_k << '\n'; |
| for (int i = 0; i < best_k; i++) { |
| if (i > 0) cout << " "; |
| cout << best_path[i]; |
| } |
| cout << '\n'; |
| } |
| } |
