Submission #588051

#	Time	Username	Problem	Language	Result	Execution time	Memory
588051		Clan328	Fountain Parks (IOI21_parks)	C++17	5 / 100	115 ms	18468 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;

void connect(int i, int j) {
    if (coords[i].x == coords[j].x) {
        u.pb(coords[i].i);
        v.pb(coords[j].i);
        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;
    for (int i = 0; i < n-1; i++) {
        bool isValid = false;
        if ((coords[i].y+2 == coords[i+1].y && coords[i].x == coords[i+1].x) || (coords[i].y == coords[i+1].y && coords[i].x+2 == coords[i+1].x)) {
            connect(i, i+1);
            isValid = true;
        } else 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 && coords[i].x+2 == coords[i+2].x)) {
            connect(i, i+2);
            isValid = true;
        }

        res &= isValid;
    }

    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;
}

Compilation message (stderr)

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:58:28: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   58 |         } else 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 && coords[i].x+2 == coords[i+2].x)) {
      |                    ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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