Submission #896835

#	Time	Username	Problem	Language	Result	Execution time	Memory
896835		Aiperiii	Port Facility (JOI17_port_facility)	C++14	22 / 100	6090 ms	33044 KiB

port_facility

#include <bits/stdc++.h>
#define int long long
#define all(x) x.begin(),x.end()
#define ff first
#define ss second
#define pb push_back
using namespace std;
const int mod=1e9+7;
signed main(){
    ios_base::sync_with_stdio();
    cin.tie(0);
    int n;
    cin>>n;
    vector <pair <int,int> > seg(n);
    vector <vector <int> > v;
    for(int i=0;i<n;i++){
        cin>>seg[i].ff>>seg[i].ss;
    }
    sort(all(seg));
    
    for(int i=0;i<n;i++){
        v.pb({seg[i].ff,i,0});
        v.pb({seg[i].ss,i,1});
    }
    sort(all(v));
    
    vector <int> g[n];
    set <pair <int,int> > st;
    for(int i=0;i<v.size();i++){
        if(v[i][2]==0){
            int ind=v[i][1];
            st.insert({seg[ind].ss,ind});
        }
        else{
            auto it=st.lower_bound({v[i][0],v[i][1]});
            it++;
            while(it!=st.end()){
                if(it->ff>v[i][0] && it->ss>v[i][1]){
                    g[v[i][1]].pb(it->ss);
                    g[it->ss].pb(v[i][1]);
                }
                it++;
            }
            st.erase({v[i][0],v[i][1]});
        }
        
    }
    
    queue <int> q;
    vector <int> vis(n);
    int cnt=0;
    for(int i=0;i<n;i++){
        if(!vis[i]){
            cnt++;
            q.push(i);
            vis[i]=1;
            while(!q.empty()){
                int v=q.front();
                q.pop();
                for(auto to : g[v]){
                    if(!vis[to]){
                        vis[to]=1;
                        q.push(to);
                    }
                }
            }
        }
    }
    for(int i=0;i<n;i++)vis[i]=0;
    bool flag=true;
    for(int i=0;i<n;i++){
        if(!vis[i]){
            q.push(i);
            vis[i]=1;
            while(!q.empty()){
                int v=q.front();
                q.pop();
                for(auto to : g[v]){
                    if(!vis[to]){
                        if(vis[v]==1)vis[to]=2;
                        if(vis[v]==2)vis[to]=1;
                        q.push(to);
                    }
                    else if(vis[to]==vis[v]){
                        flag=false;break;
                    }
                }
            }
        }
    }
    if(flag){
        int x=1;
        for(int i=0;i<cnt;i++){
            x*=2;
            x%=mod;
        }
        cout<<x<<"\n";
    }
    else cout<<0<<"\n";
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:29:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::vector<long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |     for(int i=0;i<v.size();i++){
      |                 ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22