Submission #815095

#	Time	Username	Problem	Language	Result	Execution time	Memory
815095		blackyuki	Keys (IOI21_keys)	C++17	100 / 100	972 ms	170880 KiB

keys

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<P> vp;
typedef vector<vp> vvp;
typedef vector<bool> vb;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define REP(i,k,n) for(ll i=(ll)(k);i<(ll)(n);i++)
#define all(a) a.begin(),a.end()
#define fi first
#define se second
#define pb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
const ll inf=1001001001001001001;
#include "keys.h"
struct UF{
	ll n;
	vi par,sz;
	UF(ll n_):n(n_),par(n,-1),sz(n,1){}
	void merge(ll a,ll b){
		a=root(a);b=root(b);
		if(a==b)return;
		if(sz[a]>sz[b])swap(a,b);
		par[a]=b;
		sz[b]+=sz[a];
	}
	ll root(ll i){
		if(par[i]==-1)return i;
		par[i]=root(par[i]);
		return par[i];
	}
	bool same(ll a,ll b){
		return root(a)==root(b);
	}
};
std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
	ll n=r.size(),m=u.size();
	vvp g(n);
	rep(i,m){
		g[u[i]].pb(v[i],c[i]);
		g[v[i]].pb(u[i],c[i]);
	}
	vi par(n,-1);
	rep(i,n)for(P x:g[i])if(x.se==r[i])par[i]=x.fi;
	rep(i,n)if(par[i]==-1){
		vector<int> res(n);
		rep(j,n)if(par[j]==-1)res[j]=1;
		return res;
	}
	UF uf(n);
	rep(i,n)uf.merge(i,par[i]);
	vi rt(n);
	vvi gr(n);
	vector<set<ll>> key(n);
	vector<map<ll,vi>> edge(n);
	vvi okedge(n);
	rep(i,n){
		rt[i]=i;
		gr[i].pb(i);
		key[i].insert(r[i]);
		for(auto x:g[i]){
			if(x.se==r[i])okedge[i].pb(x.fi);
			else edge[i][x.se].pb(x.fi);
		}
	}
	auto merge=[&](ll a,ll b){
		a=rt[a];b=rt[b];
		if(gr[a].size()>gr[b].size())swap(a,b);
		for(ll x:gr[a]){
			gr[b].pb(x);
			rt[x]=b;
		}
		for(ll x:okedge[a]){
			okedge[b].pb(x);
		}
		for(ll x:key[a]){
			key[b].insert(x);
			if(edge[b].count(x)){
				for(ll y:edge[b][x])okedge[b].pb(y);
				edge[b][x]=vi(0);
			}
		}
		for(auto x:edge[a]){
			if(key[b].find(x.fi)!=key[b].end()){
				for(ll y:x.se)okedge[b].pb(y);
			}
			else{
				for(ll y:x.se)edge[b][x.fi].pb(y);
			}
		}
	};
	queue<ll> que;
	vi id(n,-1);
	rep(i,n)if(id[i]==-1){
		ll cur=i;
		vi al;
		while(id[cur]==-1){
			al.pb(cur);id[cur]=i;cur=par[cur];
		}
		if(id[cur]!=i)continue;
		reverse(all(al));
		while(al.back()!=cur)al.pop_back();
		rep(j,al.size()-1)merge(al[j],al[j+1]);
		que.push(rt[al[0]]);
	}
	vi confirm;
	while(!que.empty()){
		ll i=que.front();que.pop();
		bool done=false;
		while(okedge[i].size()){
			ll j=okedge[i].back();okedge[i].pop_back();
			if(rt[j]==rt[i])continue;
			if(!uf.same(i,j)){
				uf.merge(i,j);
				par[i]=j;
				done=true;break;
			}
			vi al;
			ll cur=rt[j];
			while(cur!=i){
				al.pb(cur);cur=rt[par[cur]];
			}
			al.pb(i);
			rep(t,al.size()-1)merge(al[t],al[t+1]);
			i=rt[i];
		}
		if(!done)confirm.pb(rt[i]);
	}
	ll mi=inf;
	for(ll i:confirm)chmin(mi,(ll)(gr[i].size()));
	vector<int> res(n);
	for(ll i:confirm)if(mi==gr[i].size()){
		for(ll j:gr[i])res[j]=1;
	}
	return res;
}

Compilation message (stderr)

keys.cpp: In function 'std::vector<int> find_reachable(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
keys.cpp:139:24: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |  for(ll i:confirm)if(mi==gr[i].size()){
      |                      ~~^~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 30 / 30
• Subtask 5: 33 / 33