Submission #1062600

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062600		Unforgettablepl	Port Facility (JOI17_port_facility)	C++17	22 / 100	131 ms	93768 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;

#define int long long

const int modulo = 1e9+7;
const int LIMIT = 4e6;

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    cin >> N;
    vector<pair<int,int>> ships(N);
    for(auto&[a,b]:ships)cin>>a>>b;
    vector<vector<int>> adj(N);
    sort(ships.begin(), ships.end());
    int edges_added = 0;
    set<pair<int,int>> active;
    for(int i=0;i<N;i++) {
        auto [a,b] = ships[i];
        while(!active.empty() and active.begin()->first<a)active.erase(active.begin());
        auto final = active.emplace(b,i).first;
        for(auto iter=active.begin();iter!=final;++iter) {
            edges_added++;
            adj[i].emplace_back(iter->second);
            adj[iter->second].emplace_back(i);
        }
        if(edges_added>LIMIT) {
            cout << "0\n";
            return 0;
        }
    }
    int ans = 1;
    vector<int> visited(N,-1);
    bool works = true;
    function<void(int,int)> dfs = [&](int x,int colour) {
        if(visited[x]!=-1) {
            if(visited[x]!=colour)works=false;
            return;
        }
        visited[x]=colour;
        for(int&i:adj[x])dfs(i,colour^1);
    };
    for(int i=0;i<N;i++)if(visited[i]==-1){
        ans<<=1;
        ans%=modulo;
        dfs(i,0);
    }
    if(!works)ans=0;
    cout << ans << '\n';
}

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