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Submission #851227

# Submission time Handle Problem Language Result Execution time Memory
851227 2023-09-19T02:57:36 Z nonono Beads and wires (APIO14_beads) C++14
100 / 100
 130 ms 31224 KB 
#include <bits/stdc++.h>
using namespace std;

const int mxN = 2e5 + 10;

int n;
vector<vector<pair<int, int>>> adj(mxN);
int cost[mxN];
int dp[mxN][2][2];

void dfs(int u, int fu) {
    if(adj[u].size() == 1 && fu != -1) return ;
    
    vector<pair<int, int>> L, R;
    int sum = 0, A = 0;
    
    for(auto [v, w] : adj[u]) if(v != fu) {
        cost[v] = w;
        dfs(v, u);
        
        int x = max(dp[v][0][0], dp[v][0][1]);
        sum += x;
        
        int y = max(dp[v][1][0], dp[v][1][1]);
        
        int newA = y - x;
        A = max(A, newA);
        
        L.push_back({dp[v][0][0] + w - x, v});
        R.push_back({dp[v][1][0] + w - x, v});
    }
    
    sort(L.begin(), L.end(), greater<pair<int, int>> ());
    sort(R.begin(), R.end(), greater<pair<int, int>> ());
    
    dp[u][0][0] = sum;
    dp[u][1][0] = sum + A;
    
    if(L.size() > 1) 
        dp[u][1][0] = max(dp[u][1][0], sum + L[0].first + L[1].first);
    
    if(L[0].second != R[0].second) {
        dp[u][1][0] = max(dp[u][1][0], sum + L[0].first + R[0].first);
    } else if(L.size() > 1) {
        dp[u][1][0] = max(dp[u][1][0], sum + L[0].first + R[1].first);
        dp[u][1][0] = max(dp[u][1][0], sum + L[1].first + R[0].first);
    }
    
    dp[u][0][1] = sum + cost[u] + L[0].first;
    dp[u][1][1] = sum + cost[u] + R[0].first;
}

signed main() {

    cin.tie(0)->sync_with_stdio(0);

    cin >> n;

    for(int i = 1; i <= n - 1; i ++) {
        int u, v, w;
        cin >> u >> v >> w;

        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }

    dfs(1, -1);

    cout << max(dp[1][0][0], dp[1][1][0]) << "\n";
    return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:17:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |     for(auto [v, w] : adj[u]) if(v != fu) {
      |              ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 5112 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 1 ms 4952 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 5112 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 1 ms 4952 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4952 KB Output is correct
17 Correct 1 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4956 KB Output is correct
22 Correct 2 ms 4956 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 5112 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 1 ms 4952 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4952 KB Output is correct
17 Correct 1 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4956 KB Output is correct
22 Correct 2 ms 4956 KB Output is correct
23 Correct 3 ms 5468 KB Output is correct
24 Correct 4 ms 5468 KB Output is correct
25 Correct 3 ms 5468 KB Output is correct
26 Correct 5 ms 5892 KB Output is correct
27 Correct 5 ms 5900 KB Output is correct
28 Correct 6 ms 6212 KB Output is correct
29 Correct 7 ms 5900 KB Output is correct
30 Correct 5 ms 6176 KB Output is correct
31 Correct 6 ms 6744 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4952 KB Output is correct
2 Correct 2 ms 4956 KB Output is correct
3 Correct 2 ms 4956 KB Output is correct
4 Correct 2 ms 4956 KB Output is correct
5 Correct 2 ms 5112 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 2 ms 4956 KB Output is correct
11 Correct 1 ms 4952 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 2 ms 4956 KB Output is correct
14 Correct 2 ms 4956 KB Output is correct
15 Correct 2 ms 4956 KB Output is correct
16 Correct 2 ms 4952 KB Output is correct
17 Correct 1 ms 4956 KB Output is correct
18 Correct 2 ms 4956 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 4956 KB Output is correct
21 Correct 2 ms 4956 KB Output is correct
22 Correct 2 ms 4956 KB Output is correct
23 Correct 3 ms 5468 KB Output is correct
24 Correct 4 ms 5468 KB Output is correct
25 Correct 3 ms 5468 KB Output is correct
26 Correct 5 ms 5892 KB Output is correct
27 Correct 5 ms 5900 KB Output is correct
28 Correct 6 ms 6212 KB Output is correct
29 Correct 7 ms 5900 KB Output is correct
30 Correct 5 ms 6176 KB Output is correct
31 Correct 6 ms 6744 KB Output is correct
32 Correct 19 ms 8792 KB Output is correct
33 Correct 19 ms 8792 KB Output is correct
34 Correct 20 ms 8792 KB Output is correct
35 Correct 129 ms 20044 KB Output is correct
36 Correct 103 ms 20052 KB Output is correct
37 Correct 103 ms 19880 KB Output is correct
38 Correct 107 ms 25280 KB Output is correct
39 Correct 95 ms 20976 KB Output is correct
40 Correct 100 ms 22928 KB Output is correct
41 Correct 130 ms 31224 KB Output is correct