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Submission #971248

# Submission time Handle Problem Language Result Execution time Memory
971248 2024-04-28T08:41:53 Z kilkuwu Beads and wires (APIO14_beads) C++17
100 / 100
 135 ms 24892 KB 
#include <bits/stdc++.h>

#define nl '\n'

#ifdef LOCAL
#include "template/debug.hpp"
#else
#define dbg(...) ;
#define timer(...) ;
#endif

const int mxN = 2e5 + 5;
int dp[mxN][2][2], up[mxN];
std::vector<std::pair<int, int>> adj[mxN];
int N;

int dfs(int u, int p, int e, int b) {
  if (dp[u][e][b] != -1) return dp[u][e][b];
  std::vector<int> child;
  for (auto [v, c] : adj[u]) {
    if (v == p) continue;
    up[v] = c;
    child.push_back(v);
    dfs(v, u, 0, 0);  
    dfs(v, u, 0, 1);  
    dfs(v, u, 1, 0);  
    dfs(v, u, 1, 1);  
  }

  int& ans = dp[u][e][b];
  int sum_e_no_b = 0;
  for (int v : child) {
    sum_e_no_b += dp[v][1][0];
  }
  ans = sum_e_no_b;

  if (b) {
    for (int v : child) {
      ans = std::max(ans, sum_e_no_b - dp[v][1][0] + dp[v][1][1]);
    }

    if (child.size() >= 2) {
      std::sort(child.begin(), child.end(), [&](int i, int j) {
        return dp[i][0][0] + up[i] - dp[i][1][0] >
               dp[j][0][0] + up[j] - dp[j][1][0];
      });

      for (int v : child) {
        int cand = sum_e_no_b - dp[v][1][0] + dp[v][0][1] + up[v];
        int vv = child[0] == v ? child[1] : child[0];
        cand += dp[vv][0][0] + up[vv] - dp[vv][1][0];
        ans = std::max(ans, cand);
      }
    }
  }

  if (e) {
    for (int v : child) {
      int cand = sum_e_no_b + up[u] + up[v] + dp[v][0][b] - dp[v][1][0];
      ans = std::max(ans, cand);
    }
  }

  return ans;
}

signed main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  memset(dp, -1, sizeof(dp));
  std::cin >> N;
  for (int i = 0; i + 1 < N; i++) {
    int u, v, c;
    std::cin >> u >> v >> c;
    --u, --v;
    adj[u].emplace_back(v, c);
    adj[v].emplace_back(u, c);
  }
  std::cout << dfs(0, 0, 0, 1) << nl;
}

/*
10
4 10 2
1 2 21
1 3 13
6 7 1
7 9 5
2 4 3
2 5 8
1 6 55
6 8 34
*/

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9204 KB Output is correct
2 Correct 2 ms 9052 KB Output is correct
3 Correct 3 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9052 KB Output is correct
6 Correct 3 ms 9052 KB Output is correct
7 Correct 2 ms 9048 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 2 ms 9048 KB Output is correct
11 Correct 2 ms 9048 KB Output is correct
12 Correct 2 ms 9052 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9204 KB Output is correct
2 Correct 2 ms 9052 KB Output is correct
3 Correct 3 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9052 KB Output is correct
6 Correct 3 ms 9052 KB Output is correct
7 Correct 2 ms 9048 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 2 ms 9048 KB Output is correct
11 Correct 2 ms 9048 KB Output is correct
12 Correct 2 ms 9052 KB Output is correct
13 Correct 2 ms 9052 KB Output is correct
14 Correct 2 ms 9052 KB Output is correct
15 Correct 2 ms 9308 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9052 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9052 KB Output is correct
20 Correct 2 ms 9052 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9048 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9204 KB Output is correct
2 Correct 2 ms 9052 KB Output is correct
3 Correct 3 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9052 KB Output is correct
6 Correct 3 ms 9052 KB Output is correct
7 Correct 2 ms 9048 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 2 ms 9048 KB Output is correct
11 Correct 2 ms 9048 KB Output is correct
12 Correct 2 ms 9052 KB Output is correct
13 Correct 2 ms 9052 KB Output is correct
14 Correct 2 ms 9052 KB Output is correct
15 Correct 2 ms 9308 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9052 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9052 KB Output is correct
20 Correct 2 ms 9052 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9048 KB Output is correct
23 Correct 4 ms 9052 KB Output is correct
24 Correct 4 ms 9052 KB Output is correct
25 Correct 4 ms 9052 KB Output is correct
26 Correct 6 ms 9304 KB Output is correct
27 Correct 6 ms 9308 KB Output is correct
28 Correct 7 ms 9564 KB Output is correct
29 Correct 7 ms 9308 KB Output is correct
30 Correct 7 ms 9308 KB Output is correct
31 Correct 7 ms 10076 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9204 KB Output is correct
2 Correct 2 ms 9052 KB Output is correct
3 Correct 3 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9052 KB Output is correct
6 Correct 3 ms 9052 KB Output is correct
7 Correct 2 ms 9048 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 2 ms 9048 KB Output is correct
11 Correct 2 ms 9048 KB Output is correct
12 Correct 2 ms 9052 KB Output is correct
13 Correct 2 ms 9052 KB Output is correct
14 Correct 2 ms 9052 KB Output is correct
15 Correct 2 ms 9308 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9052 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9052 KB Output is correct
20 Correct 2 ms 9052 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9048 KB Output is correct
23 Correct 4 ms 9052 KB Output is correct
24 Correct 4 ms 9052 KB Output is correct
25 Correct 4 ms 9052 KB Output is correct
26 Correct 6 ms 9304 KB Output is correct
27 Correct 6 ms 9308 KB Output is correct
28 Correct 7 ms 9564 KB Output is correct
29 Correct 7 ms 9308 KB Output is correct
30 Correct 7 ms 9308 KB Output is correct
31 Correct 7 ms 10076 KB Output is correct
32 Correct 26 ms 10800 KB Output is correct
33 Correct 28 ms 10844 KB Output is correct
34 Correct 25 ms 10840 KB Output is correct
35 Correct 116 ms 16464 KB Output is correct
36 Correct 132 ms 16468 KB Output is correct
37 Correct 116 ms 16540 KB Output is correct
38 Correct 115 ms 18596 KB Output is correct
39 Correct 127 ms 17972 KB Output is correct
40 Correct 129 ms 17876 KB Output is correct
41 Correct 135 ms 24892 KB Output is correct