Submission #1101348

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101348		irmuun	Port Facility (JOI17_port_facility)	C++17	0 / 100	1 ms	336 KiB

port_facility

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const ll mod=1e9+7;

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n;
    cin>>n;
    vector<ll>a(n+1),b(n+1);
    vector<vector<ll>>g(n+1);
    for(ll i=1;i<=n;i++){
        cin>>a[i]>>b[i];
    }
    vector<ll>c(n+1,-1);
    for(ll i=1;i<=n;i++){
        for(ll j=i+1;j<=n;j++){
            if(b[j]<a[i]||b[i]<a[j]) continue;
            if((a[i]<b[j]&&b[j]<b[i])||(a[j]<a[i]&&b[i]<b[j])) continue;
            g[i].pb(j);
            g[j].pb(i);
        }
    }
    function <void(ll)> dfs=[&](ll x){
        for(ll y:g[x]){
            if(c[y]==-1){
                c[y]=1-c[x];
                dfs(y);
            }
        }
    };
    ll ans=1;
    for(ll i=1;i<=n;i++){
        if(c[i]==-1){
            ans=ans*2%mod;
            c[i]=0;
            dfs(i);
        }
    }
    for(ll i=1;i<=n;i++){
        for(ll j:g[i]){
            if(c[i]==c[j]){
                cout<<0;
                return 0;
            }
        }
    }
    cout<<ans;
}

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