Submission #777389

#	Time	Username	Problem	Language	Result	Execution time	Memory
777389		dxz05	Povjerenstvo (COI22_povjerenstvo)	C++17	100 / 100	545 ms	110276 KiB

Main

//#pragma GCC optimize("Ofast,O3,unroll-loops")
//#pragma GCC target("avx,avx2")

#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
//#define endl '\n'

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 5e5 + 3e2;

set<int> g[N], gr[N];
bool removed[N];

void solve(){
    int n, m;
    cin >> n >> m;

    while (m--){
        int u, v;
        cin >> u >> v;
        g[u].insert(v);
        gr[v].insert(u);
    }

    priority_queue<pair<int, int>> pq;
    for (int i = 1; i <= n; i++) pq.emplace(-1 * (int)g[i].size(), i);

    vector<int> ans;

    while (!pq.empty()){
        auto [_sz, v] = pq.top();
        pq.pop();
        if ((int) g[v].size() != _sz * -1 || removed[v]) continue;

        ans.push_back(v);
        removed[v] = true;

        for (int u : g[v]){ // v -> u
            if (removed[u]) continue;
            removed[u] = true;
            for (int x : gr[u]){
                if (removed[x]) continue;
                g[x].erase(u);
                pq.emplace(-1 * (int)g[x].size(), x);
            }
        }

        for (int u : gr[v]){ // u -> v
            removed[u] = true;
        }

    }

    cout << ans.size() << endl;
    for (int v : ans) cout << v << ' ';
    cout << endl;

}

int main(){
    clock_t startTime = clock();
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int test_cases = 1;
//    cin >> test_cases;

    for (int test = 1; test <= test_cases; test++){
        // cout << (solve() ? "YES" : "NO") << endl;
        solve();
    }

#ifdef LOCAL
    cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:71:13: warning: unused variable 'startTime' [-Wunused-variable]
   71 |     clock_t startTime = clock();
      |             ^~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 33 / 33