Submission #975355

#	Time	Username	Problem	Language	Result	Execution time	Memory
975355		LCJLY	Port Facility (JOI17_port_facility)	C++14	22 / 100	260 ms	32716 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;
 
#define int long long 
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << "  " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << "  " << j << " " << #i << "  " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<long long,long long>pii;
typedef array<int,5>pi2;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

struct DSU{
	vector<int>e;
	void init(int n){
		e=vector<int>(n,-1);
	}
	
	int get(int x){
		return e[x]<0?x:e[x]=get(e[x]);
	}
	
	bool sameSet(int x, int y){
		return get(x)==get(y);
	}
	
	bool unite(int x, int y){
		x=get(x); y=get(y);
		if(x==y) return 1;
		if(e[x]>e[y]) swap(x,y);
		e[x]+=e[y];
		e[y]=x;
		return 0;
	}
};

vector<int>adj[2005];
bool visited[2005];
const int mod=1e9+7;

void dfs(int index){
	visited[index]=true;
	for(auto it:adj[index]){
		if(visited[it]) continue;
		dfs(it);
	}
}

void solve(){
	int n;
	cin >> n;
	pii arr[n];
	for(int x=0;x<n;x++){
		cin >> arr[x].first >> arr[x].second;
	}
	
	sort(arr,arr+n);
	DSU dsu;
	dsu.init(2*n+5);
	
	for(int x=0;x<n;x++){
		for(int y=x+1;y<n;y++){
			if(arr[y].first<arr[x].second&&arr[y].second>arr[x].second){
				adj[x].push_back(y);
				adj[y].push_back(x);
				dsu.unite(x,y+n);
				dsu.unite(x+n,y);
			}
		}
	}
	
	for(int x=0;x<n;x++){
		if(dsu.sameSet(x,x+n)){
			cout << 0;
			return;
		}
	}
	
	int counter=0;
	for(int x=0;x<n;x++){
		if(!visited[x]){
			dfs(x);
			counter++;
		}
	}
	
	int ans=1;
	for(int x=0;x<counter;x++){
		ans=(ans*2)%mod;
	}
	
	cout << ans;
}
 
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t=1;
	//freopen("in.txt","r",stdin);
	//cin >> t;
	while(t--){
		solve();
	}
}

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