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Submission #971246

# Submission time Handle Problem Language Result Execution time Memory
971246 2024-04-28T08:38:40 Z kilkuwu Beads and wires (APIO14_beads) C++17
100 / 100
 163 ms 28488 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];
        dbg(v + 1, vv + 1, cand, u + 1);
        ans = std::max(ans, cand);
      }
    }
  }

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

  dbg(u + 1, e, b, ans, child);
  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 9048 KB Output is correct
2 Correct 2 ms 9048 KB Output is correct
3 Correct 2 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9060 KB Output is correct
6 Correct 2 ms 9052 KB Output is correct
7 Correct 2 ms 9068 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 3 ms 9052 KB Output is correct
11 Correct 2 ms 9068 KB Output is correct
12 Correct 2 ms 9048 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB Output is correct
2 Correct 2 ms 9048 KB Output is correct
3 Correct 2 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9060 KB Output is correct
6 Correct 2 ms 9052 KB Output is correct
7 Correct 2 ms 9068 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 3 ms 9052 KB Output is correct
11 Correct 2 ms 9068 KB Output is correct
12 Correct 2 ms 9048 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 9052 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9048 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9072 KB Output is correct
20 Correct 2 ms 9048 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9052 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB Output is correct
2 Correct 2 ms 9048 KB Output is correct
3 Correct 2 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9060 KB Output is correct
6 Correct 2 ms 9052 KB Output is correct
7 Correct 2 ms 9068 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 3 ms 9052 KB Output is correct
11 Correct 2 ms 9068 KB Output is correct
12 Correct 2 ms 9048 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 9052 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9048 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9072 KB Output is correct
20 Correct 2 ms 9048 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9052 KB Output is correct
23 Correct 4 ms 9308 KB Output is correct
24 Correct 4 ms 9308 KB Output is correct
25 Correct 4 ms 9304 KB Output is correct
26 Correct 7 ms 9564 KB Output is correct
27 Correct 6 ms 9564 KB Output is correct
28 Correct 6 ms 9664 KB Output is correct
29 Correct 6 ms 9848 KB Output is correct
30 Correct 6 ms 9564 KB Output is correct
31 Correct 7 ms 10328 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB Output is correct
2 Correct 2 ms 9048 KB Output is correct
3 Correct 2 ms 9052 KB Output is correct
4 Correct 2 ms 9052 KB Output is correct
5 Correct 2 ms 9060 KB Output is correct
6 Correct 2 ms 9052 KB Output is correct
7 Correct 2 ms 9068 KB Output is correct
8 Correct 2 ms 9052 KB Output is correct
9 Correct 2 ms 9052 KB Output is correct
10 Correct 3 ms 9052 KB Output is correct
11 Correct 2 ms 9068 KB Output is correct
12 Correct 2 ms 9048 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 9052 KB Output is correct
16 Correct 2 ms 9052 KB Output is correct
17 Correct 2 ms 9048 KB Output is correct
18 Correct 2 ms 9052 KB Output is correct
19 Correct 2 ms 9072 KB Output is correct
20 Correct 2 ms 9048 KB Output is correct
21 Correct 2 ms 9052 KB Output is correct
22 Correct 2 ms 9052 KB Output is correct
23 Correct 4 ms 9308 KB Output is correct
24 Correct 4 ms 9308 KB Output is correct
25 Correct 4 ms 9304 KB Output is correct
26 Correct 7 ms 9564 KB Output is correct
27 Correct 6 ms 9564 KB Output is correct
28 Correct 6 ms 9664 KB Output is correct
29 Correct 6 ms 9848 KB Output is correct
30 Correct 6 ms 9564 KB Output is correct
31 Correct 7 ms 10328 KB Output is correct
32 Correct 26 ms 11580 KB Output is correct
33 Correct 26 ms 11612 KB Output is correct
34 Correct 28 ms 11632 KB Output is correct
35 Correct 119 ms 19792 KB Output is correct
36 Correct 125 ms 19972 KB Output is correct
37 Correct 163 ms 20016 KB Output is correct
38 Correct 116 ms 22144 KB Output is correct
39 Correct 122 ms 21296 KB Output is correct
40 Correct 115 ms 21208 KB Output is correct
41 Correct 139 ms 28488 KB Output is correct