Submission #1082048

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082048		ALeonidou	Fountain Parks (IOI21_parks)	C++17	15 / 100	164 ms	44812 KiB

parks

#include "parks.h"
#include <bits/stdc++.h>
using namespace std;

#define ll int
#define F first
#define S second
#define pb push_back
#define sz(x) (ll)x.size()

typedef vector <ll> vi;
typedef pair <ll,ll> ii;
typedef vector <ii> vii;
typedef pair <ll, ii> iii;
typedef vector <iii> viii;
#define dbg(x) cout<<#x<<": "<<x<<endl;
#define dbg2(x,y) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<endl;
#define dbg3(x,y,z) cout<<#x<<": "<<x<<" "<<#y<<": "<<y<<" "<<#z<<": "<<z<<endl;

void printVct(vi &v){
    for (ll i =0; i<sz(v); i++){
        cout<<v[i]<<" ";
    }
    cout<<endl;
}

vector <vi> adj;
vi vis;
ll dfs(ll u){
    vis[u] = 1;
    ll ans = 1;
    for (ll i= 0; i<sz(adj[u]); i++){
        if (!vis[adj[u][i]]){
            ans += dfs(adj[u][i]);
        }
    }
    return ans;
}

void add_road(ll cur_id, ll prev_id, vi &u, vi &v){
    // dbg2(cur_id, prev_id);
    adj[cur_id].pb(prev_id);
    adj[prev_id].pb(cur_id);
    u.pb(prev_id);
    v.pb(cur_id);
}

int construct_roads(vi x, vi y) {
    ll n = sz(x);
    vi u,v,a,b;
    viii c;
    for (ll i= 0; i<n; i++){
        c.pb(iii(x[i], ii(y[i], i)));
    }
    sort(c.begin(),c.end());

    adj.assign(n, vi());

    ll prev = -10, p;
    for (p = 0; p < n && c[p].F == 2; p++){
        // dbg2(2,p);
        if (c[p].S.F - prev == 2){
            ll cur_id = c[p].S.S, prev_id = c[p-1].S.S;
            add_road(prev_id, cur_id, u, v);
            a.pb(1);
            b.pb(c[p].S.F-1);
        }
        prev = c[p].S.F;
    }

    prev = -10;
    for (; p < n; p++){
        // dbg2(4, p);
        if (c[p].S.F - prev == 2){
            ll cur_id = c[p].S.S, prev_id = c[p-1].S.S;
            add_road(prev_id, cur_id, u, v);
            a.pb(5);
            b.pb(c[p].S.F-1);
        }
        prev = c[p].S.F;
    }

    for (ll i =0; i<n; i++){
        swap(c[i].F, c[i].S.F);
    }
    sort(c.begin(), c.end());

    // cout<<endl<<endl;

    prev = -10;
    for (ll i= 0; i<n; i++){
        if (c[i].F == prev){
            // dbg2('u', i);
            ll cur_id = c[i].S.S, prev_id = c[i-1].S.S;
            add_road(prev_id, cur_id, u, v);
            a.pb(3);
            b.pb(c[i].F-1);
        }
        prev = c[i].F;
    }

    vis.assign(n, 0);
    ll d = dfs(0);
    if (d != n) return 0;
    
    build(u, v, a, b);
    return 1;
}

/*
2
2 2
2 4

4
4 4
4 6
4 2
2 4
*/

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