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Submission #557681

# Submission time Handle Problem Language Result Execution time Memory
557681 2022-05-05T18:43:53 Z Jomnoi Beads and wires (APIO14_beads) C++17
100 / 100
 315 ms 33268 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAX_N = 2e5 + 5;
const int INF = 1e9 + 7;

int N;
int ans;
vector <pair <int, int>> graph[MAX_N];
int dp[MAX_N][2], pdp[MAX_N];

void dfs(int u, int p) {
    dp[u][1] = -INF;
    for(auto [v, w] : graph[u]) {
        if(v == p) {
            continue;
        }

        dfs(v, u);

        dp[u][0] += max(dp[v][0], dp[v][1] + w);
    }

    for(auto [v, w] : graph[u]) {
        if(v == p) {
            continue;
        }

        dp[u][1] = max(dp[u][1], dp[u][0] - max(dp[v][0], dp[v][1] + w) + dp[v][0] + w);
    }
}

void dfs2(int u, int p, int pw) {
    ans = max(ans, dp[u][0] + pdp[u]);

    multiset <int> siblings;
    for(auto [v, w] : graph[u]) {
        if(v == p) {
            continue;
        }

        siblings.insert(dp[v][0] + w - max(dp[v][0], dp[v][1] + w));
        pdp[v] = max(pdp[v], dp[u][0] - max(dp[v][0], dp[v][1] + w) + pdp[u]);
        if(p != -1) {
            pdp[v] = max(pdp[v], w + pw + dp[u][0] - max(dp[v][0], dp[v][1] + w) + pdp[p] + dp[p][0] - max(dp[u][0], dp[u][1] + pw));
        }
    }

    if(siblings.size() > 1) {
        for(auto [v, w] : graph[u]) {
            if(v == p) {
                continue;
            }

            siblings.erase(siblings.lower_bound(dp[v][0] + w - max(dp[v][0], dp[v][1] + w)));
            pdp[v] = max(pdp[v], pdp[u] + dp[u][0] + w - max(dp[v][0], dp[v][1] + w) + *siblings.rbegin());
            siblings.insert(dp[v][0] + w - max(dp[v][0], dp[v][1] + w));
        }
    }

    for(auto [v, w] : graph[u]) {
        if(v != p) {
            dfs2(v, u, w);
        }
    }
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    cin >> N;
    for(int i = 1; i <= N - 1; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        graph[a].emplace_back(b, c);
        graph[b].emplace_back(a, c);
    }

    dfs(1, -1);
    dfs2(1, -1, -INF);

    cout << ans;
    return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 5028 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 4 ms 5020 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5020 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 5028 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 4 ms 5020 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5020 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 5028 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 ms 5028 KB Output is correct
17 Correct 3 ms 5032 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 4 ms 5028 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 5032 KB Output is correct
22 Correct 3 ms 4948 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 5028 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 4 ms 5020 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5020 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 5028 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 ms 5028 KB Output is correct
17 Correct 3 ms 5032 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 4 ms 5028 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 5032 KB Output is correct
22 Correct 3 ms 4948 KB Output is correct
23 Correct 6 ms 5296 KB Output is correct
24 Correct 6 ms 5264 KB Output is correct
25 Correct 5 ms 5260 KB Output is correct
26 Correct 9 ms 5672 KB Output is correct
27 Correct 9 ms 5588 KB Output is correct
28 Correct 12 ms 6128 KB Output is correct
29 Correct 11 ms 5972 KB Output is correct
30 Correct 10 ms 5936 KB Output is correct
31 Correct 9 ms 6828 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 5028 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 4 ms 5020 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 5020 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 3 ms 5028 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 ms 5028 KB Output is correct
17 Correct 3 ms 5032 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 4 ms 5028 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 5032 KB Output is correct
22 Correct 3 ms 4948 KB Output is correct
23 Correct 6 ms 5296 KB Output is correct
24 Correct 6 ms 5264 KB Output is correct
25 Correct 5 ms 5260 KB Output is correct
26 Correct 9 ms 5672 KB Output is correct
27 Correct 9 ms 5588 KB Output is correct
28 Correct 12 ms 6128 KB Output is correct
29 Correct 11 ms 5972 KB Output is correct
30 Correct 10 ms 5936 KB Output is correct
31 Correct 9 ms 6828 KB Output is correct
32 Correct 33 ms 8196 KB Output is correct
33 Correct 31 ms 8232 KB Output is correct
34 Correct 39 ms 8196 KB Output is correct
35 Correct 192 ms 18336 KB Output is correct
36 Correct 217 ms 18384 KB Output is correct
37 Correct 227 ms 18452 KB Output is correct
38 Correct 255 ms 27100 KB Output is correct
39 Correct 315 ms 28124 KB Output is correct
40 Correct 240 ms 26984 KB Output is correct
41 Correct 252 ms 33268 KB Output is correct