Submission #618744

#TimeUsernameProblemLanguageResultExecution timeMemory
618744drdilyorNewspapers (CEOI21_newspapers)C++17
100 / 100
64 ms4572 KiB
#include <bits/stdc++.h> #ifdef ONPC #include "t_debug.cpp" #else #define debug(...) 42 #endif #define sz(a) ((int)(a).size()) using namespace std; using ll = long long; const int INF = 1e9; const ll INFL = 1e18; const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count(); mt19937 rng(RANDOM); template<typename T, typename U> istream& operator>>(istream& is, pair<T, U>& p) { return is >> p.first >> p.second; } const int N = 2e5, LOGN = 17, MOD = 1e9+7; int solve() { int n; if (!(cin >> n)) { return 1; } int m; cin >> m; vector<vector<int>> adj(n); for (int i = 0;i < m; i++) { int u, v; cin >> u >> v; u--; v--; adj[u].push_back(v); adj[v].push_back(u); } if (m != n-1) {cout << "NO\n"; return 0;} if (n == 1) {cout << "YES\n1\n1\n"; return 0;} if (n == 2) {cout << "YES\n2\n1 1\n"; return 0;} bool yes = true; function<pair<int,int>(int,int)> depth = [&](int i, int p)->pair<int,int> { int res = 0, rese = i; for (int e : adj[i]) { if (e != p) { auto [d, v] = depth(e, i); if (d+1 > res) { res = d+1; rese = v; } } } return {res, rese}; }; auto [_d, d1] = depth(0, -1); auto [_dd, d2] = depth(d1, -1); vector<int> path = {d1}; vector<int> visited(n); function<bool(int)> findD = [&](int i) { if (visited[i]) return false; if (i == d2) return true; visited[i] = true; for (int e : adj[i]) { path.push_back(e); if (findD(e)) return true; path.pop_back(); } return false; }; findD(d1); debug(d1, d2, path); vector<int> res; for (int i = 1; i < sz(path)-1; i++) { int v = path[i]; int dep = 0; res.push_back(v); for (int e : adj[v]) { if (e == path[i-1] || e == path[i+1]) continue; auto [de, end] = depth(e, v); de++; if (de > 2) yes = false; if (de > 1) { res.push_back(e); res.push_back(v); } } } cout << (yes ? "YES" : "NO") << '\n'; if (yes) { cout << sz(res) * 2 << '\n'; for (int i : res) cout << i +1 << ' '; for (auto it = res.rbegin(); it != res.rend(); it++) { cout<< *it+1 << ' '; } cout << '\n'; } return 0; } signed main() { cin.tie(0)->sync_with_stdio(0); int t = 1; #ifdef ONPC t = 10000; #endif while (t-- && cin) { if (solve()) break; #ifdef ONPC cout << "____________________" << endl; #endif } return 0; } /* █████ █████ ███ ████ ▒▒███ ▒▒███ ▒▒▒ ▒▒███ ███████ ████████ ███████ ████ ▒███ █████ ████ ██████ ████████ ███▒▒███ ▒▒███▒▒███ ███▒▒███ ▒▒███ ▒███ ▒▒███ ▒███ ███▒▒███▒▒███▒▒███ ▒███ ▒███ ▒███ ▒▒▒ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒▒▒ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒███ ▒▒████████ █████ ▒▒████████ █████ █████ ▒▒███████ ▒▒██████ █████ ▒▒▒▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒███ ▒▒▒▒▒▒ ▒▒▒▒▒ ███ ▒███ ▒▒██████ ▒▒▒▒▒▒ */

Compilation message (stderr)

newspapers.cpp: In function 'int solve()':
newspapers.cpp:5:24: warning: statement has no effect [-Wunused-value]
    5 |     #define debug(...) 42
      |                        ^~
newspapers.cpp:69:5: note: in expansion of macro 'debug'
   69 |     debug(d1, d2, path);
      |     ^~~~~
newspapers.cpp:74:13: warning: unused variable 'dep' [-Wunused-variable]
   74 |         int dep = 0;
      |             ^~~
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