Submission #427093

#	Time	Username	Problem	Language	Result	Execution time	Memory
427093		kai824	Port Facility (JOI17_port_facility)	C++17	0 / 100	1 ms	332 KiB

port_facility

#include<bits/stdc++.h>
using namespace std;
#define int long long
//shouldn't need, just in case...

int eve[2000005];
list<list<int> > luol;
list<int> tmp;

int par[1000005],sz[1000005];
int getr(int x){
  if(par[x]==-1)return x;
  return par[x]=getr(par[x]);
}

bool bruh=false;
void merge(int a,int b){
  //cout<<"MERGE"<<a<<' '<<b<<'\n';
  a=getr(a);b=getr(b);
  if(a==b){
    //cout<<"path1\n";
    bruh=true;
    return;
  }
  if(sz[a]<sz[b])swap(a,b);
  par[b]=a;
  sz[a]+=sz[b];
}

int32_t main(){
  ios_base::sync_with_stdio(false);cin.tie(0);
  int n;
  cin>>n;
  int a,b;
  for(int i=0;i<n;i++){
    cin>>a>>b;
    eve[a]=(i+1);
    eve[b]=-(i+1);
    par[i+1]=-1;sz[i+1]=i;
  }
  for(int i=1;i<=(n*2);i++){
    if(eve[i]>0){
      luol.push_back(*(new list<int>));
      luol.back().push_back(eve[i]);
    }else{
      eve[i]=-eve[i];
      tmp= *(new list<int>);
      while(true){
        if(luol.size()==0){
          //cout<<"path 2\n";
          goto hell;
        }
        if(luol.back().back()==eve[i]){
          luol.back().pop_back();
          if(luol.back().size()==0)luol.pop_back();
          break;
        }
        merge(eve[i],luol.back().back());
        if(bruh)goto hell;
        tmp.splice(tmp.begin(),luol.back());
        luol.pop_back();
      }
      if(tmp.size()>0)luol.push_back(tmp);
    }

    /*for(auto x:luol){
      for(auto y:x)cout<<y<<' ';cout<<'\t';
    }cout<<'\n';*/
  }
  if(false){
    hell:;
    cout<<"0\n";
    return 0;
  }
  int ans=1;
  for(int i=1;i<=n;i++){
    if(par[i]==-1){
      ans*=2;
      ans%=1000000007;
    }
  }
  cout<<ans<<'\n';
  return 0;
}

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