Submission #815237

#	Time	Username	Problem	Language	Result	Execution time	Memory
815237		blackyuki	Fountain Parks (IOI21_parks)	C++17	100 / 100	745 ms	39724 KiB

parks

#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
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;
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);
	}
    ll getsz(ll i){
        return sz[root(i)];
    }
};
int construct_roads(std::vector<int> x, std::vector<int> y) {
    ll n=x.size();
    UF uf(n);
    vector<PP> v(n);
    rep(i,n)v[i]=PP(x[i],y[i],i);
    sort(all(v));
    vi dx={2,0},dy={0,2};
    set<P> S;
    vector<int> U, V, A, B;
    rep(k,4)rep(i,n)rep(j,2){
        P a(x[i],y[i]),b(x[i]+dx[j],y[i]+dy[j]);
        ll l=lb(v,PP(b.fi,b.se,-1));
        if(l==n)continue;
        l=get<2>(v[l]);
        if(P(x[l],y[l])!=b)continue;
        P c((a.fi+b.fi)/2,(a.se+b.se)/2);
        if(a.fi==b.fi){
            if((a.fi+a.se)%4!=k)continue;
            if((a.fi+a.se)%4==0)c.fi--;
            else c.fi++;
        }
        else{
            if((a.fi+a.se)%4!=k)continue;
            if((a.fi+a.se)%4==0)c.se++;
            else c.se--;
        }
            uf.merge(i,l);
        if(S.insert(c).se){
            U.pb(i);
            V.pb(l);
            A.pb(c.fi);
            B.pb(c.se);
        }
    }
    if(uf.getsz(0)<n)return 0;
    build(U,V,A,B);
    return 1;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30