Submission #1072849

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072849		emptypringlescan	Building Skyscrapers (CEOI19_skyscrapers)	C++17	0 / 100	9 ms	2648 KiB

skyscrapers

#include <bits/stdc++.h>
using namespace std;
struct custom_hash{
	size_t operator()(pair<long long,long long> x) const{
		return x.first*(1e9+5)+x.second;
	}
};
int dx[]={0,1,0,-1},dy[]={1,0,-1,0};
vector<int> adj[1500];
int v[1500];
int dfs(int x){
	v[x]=1;
	int ret=1;
	for(int i:adj[x]) if(!v[i]) ret+=dfs(i);
	return ret;
}
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n,t;
	cin >> n >> t;
	pair<pair<int,int>,int> arr[n];
	for(int i=0; i<n; i++){
		cin >> arr[i].first.first >> arr[i].first.second;
		arr[i].second=i;
	}
	for(int i=0; i<n; i++){
		for(int j=0; j<n; j++){
			if(abs(arr[i].first.first-arr[j].first.first)<=1&&abs(arr[i].first.second-arr[j].first.second)<=1){
				adj[i].push_back(j);
				adj[j].push_back(i);
			}
		}
	}
	if(dfs(0)!=n){
		cout << "NO";
		return 0;
	}
	mt19937 rng(999);
	shuffle(arr,arr+n,rng);
	do{
		bool can=true;
		unordered_set<pair<int,int>,custom_hash> got;
		for(int i=0; i<n; i++){
			bool nxt=false;
			if(!i) nxt=true;
			for(int j=0; j<i; j++){
				if(abs(arr[i].first.first-arr[j].first.first)<=1&&abs(arr[i].first.second-arr[j].first.second)<=1) nxt=true;
			}
			if(!nxt) can=false;
			if(!can) break;
			got.clear();
			for(int j=0; j<i; j++) got.insert(arr[j].first);
			queue<pair<int,int> > q;
			q.push(arr[i].first);
			while(!q.empty()){
				pair<int,int> x=q.front();
				q.pop();
				if(got.find(x)!=got.end()) continue;
				got.insert(x);
				if(abs(arr[i].first.first-x.first)+abs(arr[i].first.second-x.second)>n/2) break;
				for(int j=0; j<4; j++){
					pair<int,int> nx={x.first+dx[j],x.second+dy[j]};
					if(got.find(nx)==got.end()) q.push(nx);
				}
			}
			while(!q.empty()) q.pop();
		}
		if(can){
			cout << "YES\n";
			for(int i=0; i<n; i++) cout << arr[i].second+1 << ' ';
			return 0;
		}
	} while(next_permutation(arr+1,arr+n));
	assert(false);
	cout << "NO";
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 14
• Subtask 3: 0 / 12
• Subtask 4: 0 / 17
• Subtask 5: 0 / 20
• Subtask 6: 0 / 10
• Subtask 7: 0 / 19