Submission #811106

#	Time	Username	Problem	Language	Result	Execution time	Memory
811106		penguinman	Fountain Parks (IOI21_parks)	C++17	5 / 100	3570 ms	123008 KiB

parks

#include "parks.h"

#include <bits/stdc++.h>

using std::cin;
using std::cout;
using std::vector;
using std::string;
using ll = int;
using vi = vector<ll>;
using vii = vector<vi>;
using pii = std::pair<ll,ll>;
using std::endl;

#define rep(i,j,k) for(ll i=ll(j); i<ll(k); i++)
#define REP(i,j,k) for(ll i=ll(j); i<=ll(k); i++)
#define per(i,j,k) for(ll i=ll(j); i>=ll(k); i--)
#define ln "\n"
#define pb emplace_back
#define mp std::make_pair
#define all(a) a.begin(),a.end()

int construct_roads(std::vector<int> x, std::vector<int> y) {
    std::map<pii,ll> xy;
    std::map<pii,ll> rev;
    rep(i,0,x.size()) xy[mp(x[i],y[i])] = i;
    ll cnt__ = 0;
    rep(i,0,x.size()){
        vi P = {2,0}, Q = {0,2};
        vi R = {0,1}, S = {1,0};
        rep(j,0,2){
            if(xy.count(mp(x[i]+P[j], y[i]+Q[j]))){
                ll mx = x[i]+P[j]/2;
                ll my = y[i]+Q[j]/2;
                rev[mp(mx+R[j], my+S[j])] = rev[mp(mx-R[j],my-S[j])] = 0;
                cnt__++;
            }
        }
    }
    if(cnt__ != ll(x.size()-1)) return 0;
    ll N = 0;
    vi rx, ry;
    for(auto &el: rev){
        el.second = N++;
        rx.pb(el.first.first);
        ry.pb(el.first.second);
    }
    vii edge(N);
    vii eu(N), ev(N);
    rep(i,0,x.size()){
        vi P = {2,0}, Q = {0,2};
        vi R = {0,1}, S = {1,0};
        rep(j,0,2){
            if(xy.count(mp(x[i]+P[j], y[i]+Q[j]))){
                ll mx = x[i]+P[j]/2;
                ll my = y[i]+Q[j]/2;
                edge[rev[mp(mx+R[j], my+S[j])]].pb(rev[mp(mx-R[j],my-S[j])]);
                eu[rev[mp(mx+R[j], my+S[j])]].pb(i);
                ev[rev[mp(mx+R[j], my+S[j])]].pb(xy[mp(x[i]+P[j], y[i]+Q[j])]);
                edge[rev[mp(mx-R[j],my-S[j])]].pb(rev[mp(mx+R[j], my+S[j])]);
                eu[rev[mp(mx-R[j], my-S[j])]].pb(i);
                ev[rev[mp(mx-R[j], my-S[j])]].pb(xy[mp(x[i]+P[j], y[i]+Q[j])]);
            }
        }
    }
    vi cnt(N);
    rep(i,0,N) cnt[i] = edge[i].size();
    vi u,v,a,b;
    rep(k,0,N){
        if(cnt[k] != 1) continue;
        cnt[k]--;
        ll now = k;
        while(true){
            ll nex = -1;
            rep(i,0,edge[now].size()){
                ll next = edge[now][i];
                if(cnt[next] == 0) continue;
                u.pb(eu[now][i]);
                v.pb(ev[now][i]);
                a.pb(rx[now]);
                b.pb(ry[now]);
                cnt[next]--;
                if(cnt[next] == 1){
                    cnt[next]--;
                    nex = next;
                }
            }
            if(nex == -1) break;
            now = nex;
        }
    }
    rep(i,0,N){
        if(cnt[i] > 2) return 0;
    }
    rep(i,0,N){
        assert(cnt[i] == 0 || cnt[i] == 2);
        if(cnt[i] == 0) continue;
        cnt[i] = 1;
        ll now = i;
        while(true){
            ll val = -1;
            rep(j,0,edge[now].size()){
                ll next = edge[now][i];
                if(cnt[next] == 0) continue;
                u.pb(eu[now][j]);
                v.pb(ev[now][j]);
                a.pb(rx[now]);
                b.pb(ry[now]);
                val = next;
                cnt[next] = 0;
                break;
            }
            if(val == 1) break;
        }
    }
    build(u,v,a,b);
    return 1;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30