oj.uz

Submission #1022568

# Submission time Handle Problem Language Result Execution time Memory
1022568 2024-07-13T18:09:34 Z mnbvcxz123 Selotejp (COCI20_selotejp) C++17
110 / 110
 11 ms 3024 KB 
#include <bits/stdc++.h>
struct Flow {
    static constexpr int INF = 1e9;
    int n;
    struct Edge {
        int to, cap;
        Edge(int to, int cap) : to(to), cap(cap) {}
    };
    std::vector<Edge> e;
    std::vector<std::vector<int>> g;
    std::vector<int> cur, h;
    Flow(int n) : n(n), g(n) {}
    bool bfs(int s, int t) {
        h.assign(n, -1);
        std::queue<int> que;
        h[s] = 0;
        que.push(s);
        while (!que.empty()) {
            int u = que.front();
            que.pop();
            for (int i : g[u]) {
                auto [v, c] = e[i];
                if (c > 0 && h[v] == -1) {
                    h[v] = h[u] + 1;
                    if (v == t)
                        return true;
                    que.push(v);
                }
            }
        }
        return false;
    }
    int dfs(int u, int t, int f) {
        if (u == t)
            return f;
        int r = f;
        for (int &i = cur[u]; i < int(g[u].size()); ++i) {
            int j = g[u][i];
            auto [v, c] = e[j];
            if (c > 0 && h[v] == h[u] + 1) {
                int a = dfs(v, t, std::min(r, c));
                e[j].cap -= a;
                e[j ^ 1].cap += a;
                r -= a;
                if (r == 0)
                    return f;
            }
        }
        return f - r;
    }
    void addEdge(int u, int v, int c) {
        g[u].push_back(e.size());
        e.emplace_back(v, c);
        g[v].push_back(e.size());
        e.emplace_back(u, 0);
    }
    int maxFlow(int s, int t) {
        int ans = 0;
        while (bfs(s, t)) {
            cur.assign(n, 0);
            ans += dfs(s, t, INF);
        }
        return ans;
    }
};int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int n, m;
    std::cin >> n >> m;
    std::vector<std::string> s(n);
    for (int i = 0; i < n; ++i)
        std::cin >> s[i];
    Flow flow(2 * n * m + 2);
    int S = 2 * n * m, T = S + 1;
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            if (s[i][j] == '.')
                continue;
            ++ans;
            std::vector<int> v, h;
            if (i < n - 1 && s[i + 1][j] == '#')
                v.push_back(i * m + j), --ans;
            if (j < m - 1 && s[i][j + 1] == '#')
                h.push_back(i * m + j), --ans;
            if (i && s[i - 1][j] == '#')
                v.push_back((i - 1) * m + j);
            if (j && s[i][j - 1] == '#')
                h.push_back(i * m + j - 1);
            for (auto x : v)
                for (auto y : h)
                    flow.addEdge(x, y + n * m, 1);
        }
    }
    for (int i = 0; i < n * m; ++i) {
        flow.addEdge(S, i, 1);
        flow.addEdge(i + n * m, T, 1);
    }
    std::cout << ans + flow.maxFlow(S, T) << "\n";
    return 0;
}

Subtask #1
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 2 ms 2008 KB Output is correct
3 Correct 2 ms 1752 KB Output is correct
4 Correct 2 ms 2004 KB Output is correct
5 Correct 2 ms 2136 KB Output is correct
6 Correct 2 ms 2008 KB Output is correct
7 Correct 2 ms 2008 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 2 ms 2008 KB Output is correct
10 Correct 2 ms 2136 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 600 KB Output is correct
2 Correct 2 ms 2008 KB Output is correct
3 Correct 2 ms 1752 KB Output is correct
4 Correct 2 ms 2004 KB Output is correct
5 Correct 2 ms 2136 KB Output is correct
6 Correct 2 ms 2008 KB Output is correct
7 Correct 2 ms 2008 KB Output is correct
8 Correct 2 ms 1868 KB Output is correct
9 Correct 2 ms 2008 KB Output is correct
10 Correct 2 ms 2136 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 2 ms 1240 KB Output is correct
20 Correct 4 ms 1752 KB Output is correct
21 Correct 4 ms 2004 KB Output is correct
22 Correct 2 ms 2056 KB Output is correct
23 Correct 2 ms 2008 KB Output is correct
24 Correct 3 ms 2008 KB Output is correct
25 Correct 5 ms 2004 KB Output is correct
26 Correct 11 ms 2516 KB Output is correct
27 Correct 10 ms 2516 KB Output is correct
28 Correct 10 ms 3024 KB Output is correct