Submission #1137912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1137912		jackofall718	Naboj (COCI22_naboj)	C++20	0 / 110	111 ms	14716 KiB

naboj

//COCI 2021-22 ROUND 6 PROBLEM 3
#include <bits/stdc++.h>
#include <chrono>
#define ll long long int
#define endl '\n'
#define vn vector<ll>
using namespace std;
using namespace std::chrono;
const int MAX_N = 1e9 + 7;
#define pii pair<ll,ll>
const ll INF = 0x3f3f3f3f3f3f3f3f;

#define pb push_back  
#define srt(vp) sort(vp.begin(), vp.end()) 

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    auto start = high_resolution_clock::now();
    
    ll n,m;
    cin>>n>>m;
    vector <vn> adj(n+1);
    vn deg(n+1);
    
    for (int i=0;i<m;i++){
        ll u,v;
        cin>>u>>v;
        adj[u].pb(v);
        deg[v]++;
    }

    priority_queue<int, vector<int>, greater<int>> noIndegree;//so basically a min heap where elements are sorted in ascending order
    for (int i=1;i<=n;i++){
        if (deg[i]==0)noIndegree.push(i);
    }

    vn ans;

    while (!noIndegree.empty() ){
        ll u=noIndegree.top();
        noIndegree.pop();
        ans.pb(u);
        for (auto v:adj[u]){
            deg[v]--;
            if (deg[v]==0)noIndegree.push(v);
        }

    }
    
    if (ans.size() != n){
        cout<<-1<<endl;
    }
    
    else {
    cout<<n<<endl;
    for (int i=0;i<n;i++){
        cout<<ans[i]<<" "<< 1 <<endl;//initally I was alternating charges but thats wrong..if we follow the order of the topo sort simply charging them all with one crrent positive or negative works
        
    }
    }
    
    

    auto stop = high_resolution_clock::now();
    auto duration = duration_cast<microseconds>(stop - start);
    //cout << "Time taken by function: " << duration.count() << " microseconds" << endl;

    return 0;
}

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