Submission #166924

#	Time	Username	Problem	Language	Result	Execution time	Memory
166924		theStaticMind	Port Facility (JOI17_port_facility)	C++14	22 / 100	5919 ms	1048580 KiB

port_facility

#include<bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define ii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define INF 100000000000000000
#define modulo 1000000007
#define mod 998244353
#define int long long int
using namespace std;
vector<int>no(1000004);
vector<int>adj[1000004];
vector<int>vis(1000004,-1);
vector<pair<int,ii>> arr;
int F(int x){
      if(x==no[x])return x;
      return no[x]=F(no[x]);
}
bool merge(int x,int y){
      x=F(x);
      y=F(y);
      if(x==y)return false;
      no[x]=y;
      return true;
}
bool dfs(int x){
      for(int i=0;i<adj[x].size();i++){
            int y=adj[x][i];
            if(vis[y]==-1){
                  vis[y]=vis[x]^1;
                  if(dfs(y)==false)return false;
            }
            else if(vis[y]==vis[x])return false;
      }
      return true;
}
int32_t main(){
      ios_base::sync_with_stdio(false);
      cin.tie(NULL);
   //   freopen("q.gir","r",stdin);
   //   freopen("q.cik","w",stdout);
      int n,ans=1;
      for(int i=0;i<no.size();i++)no[i]=i;
      cin>>n;
      for(int i=1;i<=n;i++){
            int a,b;
            cin>>a>>b;
            arr.pb({a,{b,i}});
            arr.pb({b,{b,-i}});
      }
      sort(all(arr));
      set<ii>data;
      for(int i=0;i<arr.size();i++){
            int x=arr[i].first,y=arr[i].second.first,id=arr[i].second.second;
            if(id<0){
                  data.erase({x,-id});
            }
            else{
                  for(set<ii>::iterator itr=data.lower_bound({x,0});itr!=data.end()&&itr->first<y;itr++){
                        merge(itr->second,id);
                        adj[id].pb(itr->second);
                        adj[itr->second].pb(id);
                  }
                  data.insert({y,id});
            }
      }
      for(int i=1;i<=n;i++){
            if(F(i)==i)ans=ans*2%modulo;
      }
      for(int i=1;i<=n;i++){
            if(vis[i]>=0)continue;
            vis[i]=1;
            if(dfs(i)==false){
                  cout<<0;
                  return 0;
            }
      }
      cout<<ans;
}

Compilation message (stderr)

port_facility.cpp: In function 'bool dfs(long long int)':
port_facility.cpp:27:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i=0;i<adj[x].size();i++){
                   ~^~~~~~~~~~~~~~
port_facility.cpp: In function 'int32_t main()':
port_facility.cpp:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i=0;i<no.size();i++)no[i]=i;
                   ~^~~~~~~~~~
port_facility.cpp:53:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for(int i=0;i<arr.size();i++){
                   ~^~~~~~~~~~~

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