Submission #1055537

#	Time	Username	Problem	Language	Result	Execution time	Memory
1055537		mariaclara	Fountain Parks (IOI21_parks)	C++17	5 / 100	104 ms	37976 KiB

parks

#include "parks.h"
#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mk make_pair
#define pb push_back
#define fr first
#define sc second

int construct_roads(vector<int> x, vector<int> y) {
    int n = sz(x);
    vector<pair<pii,int>> p(n);
    vector<int> u_ans, v_ans, a_ans, b_ans;
    map<pii, int> ind;

    for(int i = 0; i < n; i++)
        p[i] = {{x[i], y[i]},i}, ind[{x[i], y[i]}] = i;

    sort(all(p));

    vector<vector<pii>> v(7);
    queue<pii> inter[7];

    for(int i = 0; i < n; i++)
        v[p[i].fr.fr].pb({p[i].fr.sc, p[i].sc});

    for(int i = 0, last = -1; i < sz(v[2]); i++) {
        if(last == -1) last = v[2][i].fr;
        if(i+1 == sz(v[2]) or v[2][i+1].fr - v[2][i].fr != 2) { 
            inter[2].push({last, v[2][i].fr});
            last = -1;
            continue; 
        }
        u_ans.pb(v[2][i].sc);
        v_ans.pb(v[2][i+1].sc);
        a_ans.pb(1);
        b_ans.pb(v[2][i].fr + 1);
    }

    for(int i = 0, last = -1; i < sz(v[6]); i++) {
        if(last == -1) last = v[6][i].fr;
        if(i+1 == sz(v[6]) or v[6][i+1].fr - v[6][i].fr != 2) { 
            inter[6].push({last, v[6][i].fr});
            last = -1;
            continue; 
        } 
        u_ans.pb(v[6][i].sc);
        v_ans.pb(v[6][i+1].sc);
        a_ans.pb(7);
        b_ans.pb(v[6][i].fr + 1);
    }

    vector<pii> to_add_1, to_add_2;
    set<pii> used; // a e b
    bool ok2 = 0, ok6 = 0;

    for(int i = 0, last = -1; i < sz(v[4]); i++) {
        int pos = v[4][i].fr;

        if(last == -1) last = pos;

        if(sz(inter[2]) and inter[2].front().sc < pos and ok2) inter[2].pop(), ok2 = 0;
        if(sz(inter[2]) and inter[2].front().fr <= pos and pos <= inter[2].front().sc) {
            if(last <= pos-2 and inter[2].front().fr <= pos-2) continue;
            u_ans.pb(v[4][i].sc);
            v_ans.pb(ind[{2,pos}]);
            a_ans.pb({3});
            b_ans.pb({pos-1});
            used.insert({3, pos-1});
            ok2 = 1;
        }

        if(sz(inter[6]) and inter[6].front().sc < pos and ok6) inter[6].pop(), ok6 = 0;
        if(sz(inter[6]) and inter[6].front().fr <= pos and pos <= inter[6].front().sc) {
            if(last <= pos-2 and inter[6].front().fr <= pos-2) continue;
            to_add_2.pb({v[4][i].sc, ind[{6,pos}]});
            ok6 = 1;
        }

        if(i+1 == sz(v[4]) or v[4][i+1].fr - v[4][i].fr != 2) last = -1;
        else if(i+1 < sz(v[4])) to_add_1.pb({v[4][i].sc, v[4][i+1].sc});
    }

    for(auto [A,B] : to_add_1) {
        if(used.count({3,y[A]+1})) {
            u_ans.pb(A);
            v_ans.pb(B);
            a_ans.pb(5);
            b_ans.pb(y[A]+1);
            used.insert({5,y[A]+1});
        }
        else {
            u_ans.pb(A);
            v_ans.pb(B);
            a_ans.pb(3);
            b_ans.pb(y[A]+1);
        }
    }

    for(auto [A,B] : to_add_2) {
        if(used.count({5,y[A]-1})) {
            u_ans.pb(A);
            v_ans.pb(B);
            a_ans.pb(5);
            b_ans.pb(y[A]+1);
        }
        else {
            u_ans.pb(A);
            v_ans.pb(B);
            a_ans.pb(5);
            b_ans.pb(y[A]-1);
        }
    }

    vector<int> edges[n];

    for(int i = 0; i < sz(u_ans); i++) 
        edges[u_ans[i]].pb(v_ans[i]), edges[v_ans[i]].pb(u_ans[i]);

    queue<int> fila;
    vector<bool> vis(n);
    fila.push(0);
    vis[0] = 1;

    while(!fila.empty()) {
        int at = fila.front();
        fila.pop();

        for(int viz : edges[at])
            if(!vis[viz]) fila.push(viz), vis[viz] = 1;
    }

    for(int i = 0; i < n; i++) if(!vis[i]) return 0;

    build(u_ans, v_ans, a_ans, b_ans);
    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