제출 #446973

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
446973		fhvirus	Building Skyscrapers (CEOI19_skyscrapers)	C++17	0 / 100	285 ms	13200 KiB

skyscrapers

// Knapsack DP is harder than FFT.
#include<bits/stdc++.h>
using namespace std;
typedef long long ll; typedef pair<int,int> pii; typedef pair<ll,ll> pll;
#define ff first
#define ss second
#define pb emplace_back
#define AI(x) begin(x),end(x)
template<class I>bool chmax(I&a,I b){return a<b?(a=b,true):false;}
template<class I>bool chmin(I&a,I b){return b<a?(a=b,true):false;} 
#ifdef OWO
#define debug(args...) SDF(#args, args)
#define OIU(args...) ostream& operator<<(ostream&O,args)
#define LKJ(S,B,E,F) template<class...T>OIU(S<T...>s){O<<B;int c=0;for(auto i:s)O<<(c++?", ":"")<<F;return O<<E;}
LKJ(vector,'[',']',i)LKJ(deque,'[',']',i)LKJ(set,'{','}',i)LKJ(multiset,'{','}',i)LKJ(unordered_set,'{','}',i)LKJ(map,'{','}',i.ff<<':'<<i.ss)LKJ(unordered_map,'{','}',i.ff<<':'<<i.ss)
template<class...T>void SDF(const char* s,T...a){int c=sizeof...(T);if(!c){cerr<<"\033[1;32mvoid\033[0m\n";return;}(cerr<<"\033[1;32m("<<s<<") = (",...,(cerr<<a<<(--c?", ":")\033[0m\n")));}
template<class T,size_t N>OIU(array<T,N>a){return O<<vector<T>(AI(a));}template<class...T>OIU(pair<T...>p){return O<<'('<<p.ff<<','<<p.ss<<')';}template<class...T>OIU(tuple<T...>t){return O<<'(',apply([&O](T...s){int c=0;(...,(O<<(c++?", ":"")<<s));},t),O<<')';}
#else
#pragma GCC optimize("Ofast")
#define debug(...) ((void)0)
#endif

// consider doing reverse
// pluck the biggest and reachable out
// then update the neighbor to touched and reachable
// priority queue maintain valid points
// reach: can be reached from outside
// touch: has a neighbor plucked

struct DSU {
	int n, s; vector<int> f;
	DSU(int n = 0) : n(n), s(n), f(n+1) { iota(AI(f), 0); }
	int F(int a){ return a == f[a] ? a : f[a] = F(f[a]); }
	int M(int a, int b){
		a = F(a), b = F(b);
		if(a == b) return false;
		f[b] = a; --s; return true;
	}
	int operator() (int a){ return F(a); }
};
struct LISAN : vector<int> {
	void done() { sort(AI()); erase(unique(AI()), end()); }
	int operator() (int a) { return lower_bound(AI(), a) - begin(); }
};

const int kN = 150051;
const int INF = 1e9 + 7;

const array<pii, 4> d4 = {pii(1, 0), pii(-1, 0), pii(0, 1), pii(0, -1)};
const array<pii, 8> d8 = {pii(1, 1), pii(1, 0), pii(1,-1), pii(0, 1), 
													pii(0, -1), pii(-1, 1), pii(-1, 0), pii(-1, -1)};

int n, t;
pii a[kN];
map<pii, int> mp;
vector<int> adj[kN];

vector<int> getOuter(){
	LISAN lr, lc;
	for(int i = 1; i <= n; ++i){ lr.pb(a[i].ff); lc.pb(a[i].ss); }
	lr.done(); lc.done();

	vector<int> ans;
	vector<int> mr(lr.size(), INF), mc(lc.size(), INF);
	vector<int> Mr(lr.size(), -INF), Mc(lc.size(), -INF);
	for(int i = 1; i <= n; ++i){
		auto[r, c] = a[i]; r = lr(r); c = lc(c);
		chmin(mr[r], c); chmin(mc[c], r);
		chmax(Mr[r], c); chmax(Mc[c], r);
	}
	for(int i = 0; i < lr.size(); ++i)
		if(mr[i] != INF) ans.pb(mp[pii(lr[i], lc[mr[i]])]);
	for(int i = 0; i < lr.size(); ++i)
		if(Mr[i] != -INF) ans.pb(mp[pii(lr[i], lc[Mr[i]])]);
	for(int i = 0; i < lc.size(); ++i)
		if(mc[i] != INF) ans.pb(mp[pii(lr[mc[i]], lc[i])]);
	for(int i = 0; i < lc.size(); ++i)
		if(Mc[i] != -INF) ans.pb(mp[pii(lr[Mc[i]], lc[i])]);
	sort(AI(ans)); ans.erase(unique(AI(ans)), end(ans));

	debug(mr);
	debug(mc);
	debug(Mr);
	debug(Mc);
	debug(ans);
	return ans;
}

signed main(){
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin >> n >> t;
	DSU dsu(n);

	for(int r, c, i = 1; i <= n; ++i){
		cin >> r >> c;
		a[i] = pii(r, c);
		mp[pii(r, c)] = i;
	}

	for(int i = 1; i <= n; ++i){
		auto [r, c] = a[i];
		for(auto [dr, dc]: d8){
			pii u(r + dr, c + dc);
			if(mp.count(u)){
				int v = mp[u];
				if(dsu.M(i, v)){
					adj[i].pb(v);
					adj[v].pb(i);
				}
			}
		}
	}

	for(int i = 1; i <= n; ++i) debug(i, adj[i]);

	if(dsu.s != 1){ cout << "NO"; return 0; }
	cout << "YES\n";

	vector<int> out = getOuter();
	vector<int> ans, vis(n + 1, 0);
	priority_queue<int> pq;
	for(int i: out){
		pq.push(i);
		vis[i] = 1;
	}

	while(!pq.empty()){
		int u = pq.top(); pq.pop();
		debug(u);
		vis[u] = 2; ans.pb(u);
		for(int v: adj[u]){
			if(vis[v] > 0) continue;
			vis[v] = 1; pq.push(v);
		}
	}

	reverse(AI(ans));
	for(int i: ans) cout << i << ' ';

	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

skyscrapers.cpp: In function 'std::vector<int> getOuter()':
skyscrapers.cpp:71:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |  for(int i = 0; i < lr.size(); ++i)
      |                 ~~^~~~~~~~~~~
skyscrapers.cpp:73:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |  for(int i = 0; i < lr.size(); ++i)
      |                 ~~^~~~~~~~~~~
skyscrapers.cpp:75:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |  for(int i = 0; i < lc.size(); ++i)
      |                 ~~^~~~~~~~~~~
skyscrapers.cpp:77:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |  for(int i = 0; i < lc.size(); ++i)
      |                 ~~^~~~~~~~~~~

• 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