Submission #622382

#	Time	Username	Problem	Language	Result	Execution time	Memory
622382		Hanksburger	Port Facility (JOI17_port_facility)	C++17	100 / 100	1697 ms	89308 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;
const int mod=1e9+7;
pair<int, int> a[1000005];
set<pair<int, int> > s;
int p[2000005];
int f(int x)
{
    return p[x]==x?x:(p[x]=f(p[x]));
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, ans=1;
    cin >> n;
    for (int i=1; i<=n; i++)
        cin >> a[i].first >> a[i].second;
    sort(a+1, a+n+1);
    for (int i=1; i<=n*2; i++)
        p[i]=i;
    for (int i=1; i<=n; i++)
    {
        auto itr1=s.lower_bound({a[i].first, 0}), itr2=s.lower_bound({a[i].second, 0});
        for (auto itr=itr1; itr!=itr2; itr++)
        {
            p[f(itr->second+n)]=f(i);
            p[f(itr->second)]=f(i+n);
            if (f(itr->second)==f(prev(itr2)->second))
                break;
        }
        s.insert({a[i].second, i});
    }
    for (int i=1; i<=n; i++)
    {
        if (f(i)==f(i+n))
        {
            cout << 0;
            return 0;
        }
    }
    for (int i=1; i<=n; i++)
        if (f(i)==i)
            ans=ans*2%mod;
    cout << ans;
    return 0;
}

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