Submission #892626

#	Time	Username	Problem	Language	Result	Execution time	Memory
892626		ReLice	Port Facility (JOI17_port_facility)	C++14	10 / 100	147 ms	290980 KiB

port_facility

#include <bits/stdc++.h>
#define ll int
#define str string
#define ins insert
#define ld long double
#define pb push_back
#define pf push_front
#define pof pop_front()
#define pob pop_back()
#define lb lower_bound
#define ub upper_bound
#define endl "\n"
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define sz size()
#define bc back()
//#define ar array
#define vll vector<ll> 
using namespace std;/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;*/
template <class _T>
bool chmin(_T &x, const _T &y){
    if(x>y){
        x=y;
        return true;
    }
    return false;
}
template <class _T>
bool chmax(_T &x, const _T &y){
    bool flag=false;
    if (x<y){
        x=y;flag|=true;
    }
    return flag;
}
//#define ordered_set tree<ll, null_type,less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>
void fre(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
void start(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}
//const ll inf=2e18+7;
const ll mod=1e9+7;
const ll N=2e6+7;
const ld eps=1e-9;
vector<vector<pair<ll,ll>>> t(N*4),ar(N);
vector<vll> g(N);
ll comp[N];
ll val[N];
void build(ll v,ll tl,ll tr){
	if(tl==tr){
		for(auto i : ar[tl])t[v].pb(i);
		return;
	}
	ll tm=(tl+tr)/2;
	build(v*2,tl,tm);
	build(v*2+1,tm+1,tr);
	for(auto i : t[v*2])t[v].pb(i);
	for(auto i : t[v*2+1])t[v].pb(i);
}
vector<pair<ll,ll> > get(ll v,ll tl,ll tr,ll l,ll r){
	if(tl>r || tr<l)return {};
	if(l<=tl && tr<=r)return t[v];
	ll tm=(tl+tr)/2;
	vector<pair<ll,ll>> vv;
	for(auto i : get(v*2,tl,tm,l,r))vv.pb(i);
	for(auto i : get(v*2+1,tm+1,tr,l,r))vv.pb(i);
	return vv;
}
void dfs(ll v,ll c){
	comp[v]=c;
	for(auto i : g[v]){
		if(comp[i])continue;
		dfs(i,c);
	}
}
void solve(){
	ll i;
	ll n;
	ll a,b;
	cin>>n;
	vector<vector<pair<ll,ll>>> cur(n*2+5);
	for(i=1;i<=n;i++){
		cin>>a>>b;
		ar[b].pb({a,i});
		cur[a].pb({b,i});
	}
	build(1,1,n*2);
	for(i=1;i<=2*n;i++){
		for(auto j : cur[i]){
			vector<pair<ll,ll>> v=get(1,1,n*2,i,j.fr);
			sort(all(v));
			for(auto q : v){
				if(q.fr>=i)break;
				g[q.sc].pb(j.sc);
				g[j.sc].pb(q.sc);
				val[j.sc]=max(val[q.sc]+1,val[j.sc]);
			}
			if(val[j.sc]>1){
				cout<<0<<endl;
				return;
			}
		}
		for(auto j : ar[i]){
			for(auto to : g[j.sc]){
				val[to]--;
			}
		}
	}
	ll c=0;
	for(i=1;i<=n;i++){
		if(comp[i]==0)dfs(i,++c);
	}
	ll x=1;
	for(i=1;i<=c;i++){
		x*=2;
		x%=mod;
	}
	cout<<x<<endl;
}
signed main(){
	start();
    ll t=1;
	//cin>>t;
    while(t--) solve();
    return 0;
}
/*
1
6
5 4 3 2 1 0





*/

Compilation message (stderr)

port_facility.cpp: In function 'void fre(std::string)':
port_facility.cpp:42:27: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 | void fre(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
port_facility.cpp:42:64: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 | void fre(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                                                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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