Submission #535661

#	Time	Username	Problem	Language	Result	Execution time	Memory
535661		Antekb	Port Facility (JOI17_port_facility)	C++14	10 / 100	56 ms	99208 KiB

port_facility

#include<bits/stdc++.h>
using namespace std;
#define st first
#define nd second
typedef pair<int, int> pii;
const int N=1<<21;
pii seg[N];
vector<int> tab[N+N];
void insert(int id){
	int l=seg[id].st+N, r=seg[id].nd+1+N;
	for(;l<r; l>>=1, r>>=1){
		if(l&1)tab[l++].push_back(id);
		if(r&1)tab[--r].push_back(id);
	}
}
int vis[N];
void dfs(int s){
	vector<int> V;
	V.push_back(s);
	vis[s]=1;
	for(int i=0; i<V.size(); i++){
		int v=V[i];
		int l=seg[v].st+N, r=seg[v].nd+N;
		while(l){
			for(auto u:tab[l]){
				if(!vis[u]){
					vis[u]=1;
					V.push_back(u);
				}
			}
			tab[l].clear();
			l/=2;
		}
		while(r){
			for(auto u:tab[r]){
				if(!vis[u]){
					vis[u]=1;
					V.push_back(u);
				}
			}
			tab[r].clear();
			r/=2;
		}
	}
}
int lew[N], pra[N];

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	int n;
	cin>>n;
	for(int i=0; i<n; i++){
		cin>>seg[i].st>>seg[i].nd;
		insert(i);
	}
	int ile=0, ans=1;
	int mod=1e9+7;
	vector<pii> V2;
	for(int i=0; i<n; i++){
		V2.push_back({seg[i].st-seg[i].nd, i});
	}
	sort(V2.begin(), V2.end());
	for(int i=0; i<n; i++){
		int j=V2[i].nd;
		if(!vis[j]){
			ile++;
			ans*=2;
			if(ans>=mod)ans-=mod;
			dfs(j);
		}
	}
	bool czy=1;
	vector<pair<pii, int> > V;
	for(int i=0; i<n; i++){
		V.push_back({seg[i], i});
	}
	sort(V.begin(), V.end());
	set<int> S;
	for(int i=0; i<n; i++){
		int a=V[i].st.st, b=V[i].st.nd, c=V[i].nd;
		S.insert(b);
		auto it=S.find(b);
		if(it!=S.begin()){
			it--;
			lew[c]=*it;
		}
		else lew[c]=a;
	}
	S.clear();
	for(int i=0; i<n; i++)swap(V[i].st.st, V[i].st.nd);
	sort(V.begin(), V.end());
	for(int i=n-1; i>=0; i--){
		int a=V[i].st.st, b=V[i].st.nd, c=V[i].nd;
		//cerr<<a<<" "<<b<<" "<<c<<endl;
		S.insert(b);
		auto it=S.find(b);
		it++;
		if(it!=S.end()){
			pra[c]=*it;
		}
		else pra[c]=a;
	}
	for(int i=0; i<n; i++){
		//cerr<<pra[i]<<" "<<lew[i]<<endl;
		if(pra[i]<lew[i])ans=0;
	}
	cout<<ans;
}

Compilation message (stderr)

port_facility.cpp: In function 'void dfs(int)':
port_facility.cpp:21:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  for(int i=0; i<V.size(); i++){
      |               ~^~~~~~~~~
port_facility.cpp: In function 'int main()':
port_facility.cpp:72:7: warning: unused variable 'czy' [-Wunused-variable]
   72 |  bool czy=1;
      |       ^~~

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