oj.uz

Submission #695117

# Submission time Handle Problem Language Result Execution time Memory
695117 2023-02-04T18:18:26 Z finn__ Stranded Far From Home (BOI22_island) C++17
0 / 100
 1000 ms 21552 KB 
#include <bits/stdc++.h>
using namespace std;

struct DSU
{
    vector<int64_t> parent, weight;
    vector<bool> is_bad;

    DSU(size_t n, vector<int64_t> const &s)
    {
        parent = vector<int64_t>(n, -1);
        weight = vector<int64_t>(s.begin(), s.end());
        is_bad = vector<bool>(n, 0);
    }

    void update_bad(int u)
    {
        if (parent[u] >= 0)
        {
            is_bad[u] = is_bad[u] || is_bad[parent[u]];
            update_bad(parent[u]);
        }
    }

    int root(int u)
    {
        if (parent[u] < 0)
            return u;
        return parent[u] = root(parent[u]);
    }

    void merge(int u, int v)
    {
        update_bad(u), update_bad(v);
        u = root(u), v = root(v);
        if (u == v)
            return;

        weight[u] += weight[v];
        parent[u] += parent[v];
        parent[v] = u;
    }

    void mark_bad(int u) { is_bad[root(u)] = 1; }

    int64_t component_weight(int u)
    {
        update_bad(u);
        return weight[root(u)];
    }

    bool get_bad(int u)
    {
        update_bad(u);
        return is_bad[u];
    }
};

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    size_t n, m;
    cin >> n >> m;

    vector<int64_t> s(n);
    for (int64_t &x : s)
        cin >> x;

    vector<pair<int64_t, unsigned>> nodes(n);
    for (size_t i = 0; i < n; i++)
        nodes[i] = {s[i], i};
    sort(nodes.begin(), nodes.end());

    vector<vector<unsigned>> g(n);
    for (size_t i = 0; i < m; i++)
    {
        unsigned u, v;
        cin >> u >> v;
        g[u - 1].push_back(v - 1);
        g[v - 1].push_back(u - 1);
    }

    DSU dsu(n, s);

    for (auto const &[x, u] : nodes)
    {
        for (unsigned const &v : g[u])
        {
            if (s[v] <= x)
            {
                if (dsu.component_weight(v) < x)
                    dsu.mark_bad(v);
                dsu.merge(u, v);
            }
        }
    }

    for (size_t i = 0; i < n; i++)
        cout << (unsigned)!dsu.get_bad(i);
    cout << '\n';
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 320 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 2 ms 456 KB Output is correct
6 Correct 2 ms 464 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Incorrect 4 ms 468 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Execution timed out 1072 ms 21480 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 170 ms 21492 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Incorrect 192 ms 21552 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 320 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 2 ms 456 KB Output is correct
6 Correct 2 ms 464 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Incorrect 4 ms 468 KB Output isn't correct
10 Halted 0 ms 0 KB -