Submission #781663

#	Time	Username	Problem	Language	Result	Execution time	Memory
781663		andecaandeci	Naboj (COCI22_naboj)	C++17	0 / 110	414 ms	24836 KiB

naboj

#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define pii pair<int, int>
#define uh pair<int,pii>
#define fr first
#define sc second
#define all(x) x.begin(), x.end()
using namespace std;

const int N = 2e5+5;
const int M = 5e5+5;

vector<int> adj[N];
vector<int> opp[N];
vector<int> marker;
vector<int> par;
vector<bool> sequenced;
vector<vector<int>> ano;
queue<int> q;

vector<int> bfsfront(int x);

vector<int> bfsback(int x) {
    vector<int> vv;
    vv.pb(x);
    q.push(x);
    while(!q.empty()) {
        int cur = q.front(); q.pop();
        sequenced[cur] = 1;
        for (auto item : opp[cur]) {
            if (!sequenced[item] and opp[item].size()) {
                if (adj[item].size() > 1) {
                    vector<int> neww;
                    for (auto item : bfsfront(item)) {
                        neww.pb(item);
                    }
                    reverse(neww.begin(), neww.end());
                    for (auto item2 : neww) vv.pb(item2);
                    q.push(item);
                } else {
                    q.push(item);
                    vv.pb(item);
                }
            }
        }
    }
    return vv;
}

vector<int> bfsfront(int x) {
    vector<int> vv;
    vv.pb(x);
    q.push(x);
    while(!q.empty()) {
        int cur = q.front(); q.pop();
        sequenced[cur] = 1;
        for (auto item : adj[cur]) {
            if (!sequenced[item] and adj[item].size()) { 
                if(opp[item].size() > 1) {
                    vector<int> neww;
                    for (auto item : bfsback(item)) {
                        neww.pb(item);
                    }
                    reverse(neww.begin(), neww.end());
                    for (auto item2 : neww) vv.pb(item2);
                    q.push(item);
                } else {
                    q.push(item);
                    vv.pb(item);
                }
            }
        }
    }
    return vv;
}

bool dfs(int x) {
    marker[x] = 1;
    for (auto item : adj[x]) {
        if (!marker[item]) {
            par[item] = x;
            if (dfs(item)) return true;
        } else if (marker[item] == 1) return true;
    }
    marker[x] = 2;
    return false;
}

signed main() {
    int n, m; cin >> n >> m;
    marker.assign(n+1, 0);
    par.assign(n+1, -1);
    sequenced.assign(n+1, 0);
    // if going forward then 

    for (int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        adj[b].pb(a);
        opp[a].pb(b);
    }
    for (int i = 1; i <= n; i++) {
        if (!marker[i]) {
            if (dfs(i)) {
                cout << -1 << endl;
                return 0;
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        if (opp[i].size() and adj[i].size() and !sequenced[i]) {
            vector<int> v;
            for (auto item : bfsback(i)) {
                v.pb(item);
            }
            reverse(all(v));
            v.pop_back();
            for (auto item : bfsfront(i)) {
                v.pb(item);
            }

            ano.pb(v);
        }
    }  

    cout << n << endl;
    for (auto vec : ano) {
        for (auto item : vec) cout << item << " " << 1 << endl;
    }

    for (int i = n; i >= 1; i--) {
        if (!sequenced[i]) {
            cout << i << " " << (adj[i].size() == 0) << endl;
        }
    }
    
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 25
• Subtask 3: 0 / 70