Submission #588064

#	Time	Username	Problem	Language	Result	Execution time	Memory
588064		Clan328	Fountain Parks (IOI21_parks)	C++17	15 / 100	199 ms	26352 KiB

parks

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

using namespace std;

#define pb push_back

struct Coord {
    int x, y, i;

    bool operator<(Coord other) const  {
        if (y == other.y) {
            return x < other.x;
        }
        return y < other.y;
    }
};

int n;
vector<Coord> coords;
std::vector<int> u, v, a, b;

vector<int> link;

int find(int x) {
    if (link[x] != x) link[x] = find(link[x]);
    return link[x];
}

void unite(int a, int b) {
    int x = find(a), y = find(b);
    link[x] = y;
}

bool same(int a, int b) {
    return find(a) == find(b);
}

void connect(int i, int j) {
    if (coords[i].x == coords[j].x) {
        u.pb(coords[i].i);
        v.pb(coords[j].i);
        if (coords[i].x == 4)
            a.pb(coords[i].x+1);
        else
            a.pb(coords[i].x-1);
        b.pb(coords[i].y+1);
    } else if (coords[i].y == coords[j].y) {
        u.pb(coords[i].i);
        v.pb(coords[j].i);
        a.pb(coords[i].x+1);
        b.pb(coords[i].y-1);
    }
}

int construct_roads(std::vector<int> x, std::vector<int> y) {
    if (x.size() == 1) {
        build({}, {}, {}, {});
        return 1;
    }  

    n = x.size();

    vector<pair<int, int>> yi(n);
    coords = vector<Coord>(n);
    for (int i = 0; i < n; i++) {
        coords[i] = {x[i], y[i], i};
    }

    sort(coords.begin(), coords.end());
    bool res = true;
    link = vector<int>(n);
    iota(link.begin(), link.end(), 0);
    for (int i = 0; i < n-1; i++) {
        if ((coords[i].y+2 == coords[i+1].y && coords[i].x == coords[i+1].x) || (coords[i].y == coords[i+1].y && abs(coords[i+1].x-coords[i].x) == 2)) {
            connect(i, i+1);
            unite(i, i+1);
        }
        if (i+2 < n && ((coords[i].y+2 == coords[i+2].y && coords[i].x == coords[i+2].x) || (coords[i].y == coords[i+2].y && abs(coords[i+2].x-coords[i].x) == 2))) {
            connect(i, i+2);
            unite(i, i+2);
        }
    }
    
    for (int i = 0; i < n-1; i++) {
        res &= find(i) == find(i+1);
    }

    if (!res) return 0;

    
    // int maxY = 0;
    // for (int i = 0; i < y.size(); i++) maxY = max(maxY, y[i]);

    // vvi mat(maxY/2-1, vi(3)), matIdx(maxY/2-1, vi(3));
    // for (int i = 0; i < x.size(); i++) {
    //     mat[x[i]/2-1][y[i]/2-1] = 1;
    //     matIdx[x[i]/2-1][y[i]/2-1] = i;
    // }



    build(u, v, a, b);
    return 1;
}

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