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Submission #375892

# Submission time Handle Problem Language Result Execution time Memory
375892 2021-03-10T08:09:28 Z KoD Beads and wires (APIO14_beads) C++17
100 / 100
 415 ms 48096 KB 
#include <bits/stdc++.h>

template <class T>
using Vec = std::vector<T>;

template <class F>
struct RecLambda: private F {
    explicit RecLambda(F &&f): F(std::forward<F>(f)) { }
    template <class... Args>
    decltype(auto) operator () (Args&&... args) const {
        return F::operator()(*this, std::forward<Args>(args)...);
    }
};

constexpr int INF = 2000000000;

int main() {
    int N;
    std::cin >> N;
    Vec<Vec<std::pair<int, int>>> graph(N);
    for (int i = 1; i < N; ++i) {
        int a, b, c;
        std::cin >> a >> b >> c;
        a -= 1;
        b -= 1;
        graph[a].emplace_back(b, c);
        graph[b].emplace_back(a, c);
    }
    Vec<Vec<int>> a(N), b(N);
    for (int i = 0; i < N; ++i) {
        a[i].resize(graph[i].size());
        b[i].resize(graph[i].size());
    }
    RecLambda([&](const auto dfs, const int u, const int p) -> std::pair<int, int> {
        int sum = 0, dif = INF;
        for (int i = 0; i < (int) graph[u].size(); ++i) {
            const auto [v, c] = graph[u][i];
            if (v == p) {
                continue;
            }
            const auto [t1, t2] = dfs(v, u);
            a[u][i] = t1 + c;
            b[u][i] = std::max(t1, t2 + c);
            sum += b[u][i];
            dif = std::min(dif, b[u][i] - a[u][i]);
        }
        return std::make_pair(sum, sum - dif);
    })(0, -1);
    int ans = 0;
    RecLambda([&](const auto dfs, const int u, const int p, const int up_t1, const int up_t2) -> void {
        const auto size = (int) graph[u].size();
        int sum = 0;
        for (int i = 0; i < size; ++i) {
            const auto [v, c] = graph[u][i];
            if (v == p) {
                a[u][i] = up_t1 + c;
                b[u][i] = std::max(up_t1, up_t2 + c);
            }
            sum += b[u][i];
        }
        ans = std::max(ans, sum);
        Vec<int> pref(size + 1, INF);
        Vec<int> suff(size + 1, INF);
        for (int i = 0; i < size; ++i) {
            pref[i + 1] = std::min(pref[i], b[u][i] - a[u][i]);
            suff[i + 1] = std::min(suff[i], b[u][size - i - 1] - a[u][size - i - 1]);
        }
        for (int i = 0; i < size; ++i) {
            const auto [v, c] = graph[u][i];
            if (v == p) {
                continue;
            }
            const auto t1 = sum - b[u][i];
            const auto t2 = t1 - std::min(pref[i], suff[size - i - 1]);
            dfs(v, u, t1, t2);
        }
    })(0, -1, 0, 0);
    std::cout << ans << '\n';
    return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 7 ms 1260 KB Output is correct
24 Correct 7 ms 1260 KB Output is correct
25 Correct 7 ms 1260 KB Output is correct
26 Correct 13 ms 2176 KB Output is correct
27 Correct 13 ms 2156 KB Output is correct
28 Correct 12 ms 2284 KB Output is correct
29 Correct 14 ms 2540 KB Output is correct
30 Correct 13 ms 2284 KB Output is correct
31 Correct 14 ms 3052 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 7 ms 1260 KB Output is correct
24 Correct 7 ms 1260 KB Output is correct
25 Correct 7 ms 1260 KB Output is correct
26 Correct 13 ms 2176 KB Output is correct
27 Correct 13 ms 2156 KB Output is correct
28 Correct 12 ms 2284 KB Output is correct
29 Correct 14 ms 2540 KB Output is correct
30 Correct 13 ms 2284 KB Output is correct
31 Correct 14 ms 3052 KB Output is correct
32 Correct 84 ms 9580 KB Output is correct
33 Correct 83 ms 9728 KB Output is correct
34 Correct 80 ms 9708 KB Output is correct
35 Correct 406 ms 38252 KB Output is correct
36 Correct 410 ms 38252 KB Output is correct
37 Correct 415 ms 37996 KB Output is correct
38 Correct 348 ms 41464 KB Output is correct
39 Correct 333 ms 41420 KB Output is correct
40 Correct 340 ms 41172 KB Output is correct
41 Correct 415 ms 48096 KB Output is correct