Submission #796307

#	Time	Username	Problem	Language	Result	Execution time	Memory
796307		t6twotwo	Fountain Parks (IOI21_parks)	C++17	15 / 100	125 ms	24408 KiB

parks

#include "parks.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
struct dsu {
    int n;
    vector<int> p, s;
    dsu(int n) : n(n), p(n), s(n, 1) {
        iota(p.begin(), p.end(), 0);
    }
    int find(int x) {
        return x == p[x] ? x : p[x] = find(p[x]);
    }
    int size(int x) {
        return s[find(x)];
    }
    bool same(int x, int y) {
        return find(x) == find(y);
    }
    bool unite(int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) {
            return 0;
        }
        if (s[x] > s[y]) {
            swap(x, y);
        }
        p[x] = y;
        s[y] += s[x];
        return 1;
    }
};
int construct_roads(vector<int> X, vector<int> Y) {
    int N = X.size();
    vector f(5, vector(200003, -1));
    for (int i = 0; i < N; i++) {
        f[X[i]][Y[i]] = i;
    }
    dsu uf(N);
    vector<int> u, v, a, b;
    for (int y = 2; y <= 200000; y += 2) {
        for (int x = 2; x <= 4; x += 2) {
            if (f[x][y] != -1 && f[x][y + 2] != -1) {
                u.push_back(f[x][y]);
                v.push_back(f[x][y + 2]);
                a.push_back(2 * x - 3);
                b.push_back(y + 1);
                uf.unite(f[x][y], f[x][y + 2]);
            }
        }
        if (f[2][y] != -1 && f[4][y] != -1) {
            u.push_back(f[2][y]);
            v.push_back(f[4][y]);
            a.push_back(3);
            b.push_back(y - 1);
            uf.unite(f[2][y], f[4][y]);
        }
    }
    if (uf.size(0) != N) {
        return 0;
    }
    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