Submission #1062546

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062546		Unforgettablepl	Port Facility (JOI17_port_facility)	C++17	22 / 100	6052 ms	32856 KiB

port_facility

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

#define int long long

const int modulo = 1e9+7;

bool check_intersection(pair<int,int> a,pair<int,int> b) {
    return (a.first<b.first and b.first<a.second and a.second<b.second)
        or (b.first<a.first and a.first<b.second and b.second<a.second);
}

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);
    for(int u=0;u<N;u++) {
        for(int v=u+1;v<N;v++) {
            if(check_intersection(ships[u],ships[v])) {
                adj[u].emplace_back(v);
                adj[v].emplace_back(u);
            }
        }
    }
    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