Submission #953546

#	Time	Username	Problem	Language	Result	Execution time	Memory
953546		Darren0724	Port Facility (JOI17_port_facility)	C++17	0 / 100	9 ms	16476 KiB

port_facility

#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace std;
#define LCBorz ios_base::sync_with_stdio(false); cin.tie(0);
#define int long long
#define all(x) x.begin(), x.end()
#define endl '\n'
const int N=200005;
const int INF=1e18;
const int mod=1e9+7;
struct DSU{
    vector<int> pa,sz;
    DSU(int n){
        pa.resize(n<<1);
        sz.resize(n<<1);
    }
    int Find(int k){
        return pa[k]=Find(pa[k])?k:pa[k]=Find(pa[k]);
    }
    void unite(int a,int b){
        a=Find(a),b=Find(b);
        if(a==b)return;
        if(sz[a]>sz[b])swap(a,b);
        pa[a]=b;
        sz[b]+=sz[a];
    }
    int onion(int a,int b){
        unite(a,b+N);
        unite(a+N,b);
        return Find(a)==Find(a+N);
    } 
};
vector<int> adj[N],vis(N),dis(N);
void dfs(int k,int pa){
    vis[k]=1;
    for(int j:adj[k]){
        if(j==pa)continue;
        if(!vis[j]){
            dis[j]=dis[k]+1;
            dfs(j,k);
        }
        else if(dis[j]%2==dis[k]%2){
            cout<<0<<endl;
            exit(0);
        }
    }
} 
int32_t main() {
    LCBorz;
    int n;cin>>n;
    vector<int> a(n),b(n);
    for(int i=0;i<n;i++){
        cin>>a[i]>>b[i];
    }
    int cnt1=0;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(i==j)continue;
            int cnt=(a[j]>=a[i]&&a[j]<=b[i])+(b[j]>=a[i]&&b[j]<=b[i]);
            if(cnt==1){
                cnt1++;
                adj[i].push_back(j);
            }
        }
    }
    assert(cnt1<=5*n);
    int ans=1;
    for(int i=0;i<n;i++){
        if(!vis[i]){
            ans=ans*2%mod;
            dfs(i,i);
        }
    }
    cout<<ans<<endl;
    

    return 0;
}

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