Submission #1183457

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183457		avighna	Designated Cities (JOI19_designated_cities)	C++20	9 / 100	143 ms	56984 KiB

designated_cities

#include <bits/stdc++.h>

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int n;
  std::cin >> n;
  std::vector<std::vector<std::pair<int, std::pair<long long, long long>>>> adj(
      n + 1);
  long long tot = 0;
  for (int i = 0, a, b, c, d; i < n - 1; ++i) {
    std::cin >> a >> b >> c >> d;
    adj[a].push_back({b, {c, d}});
    adj[b].push_back({a, {d, c}});
    tot += c + d;
  }

  std::vector<long long> path_up(n + 1), path_down(n + 1);
  long long up = 0;
  auto dfs = [&](auto &&self, int u, int p) -> void {
    for (auto &[i, pr] : adj[u]) {
      if (i == p) {
        continue;
      }
      auto [c, d] = pr;
      up += d;
      path_up[i] = path_up[u] + d;
      path_down[i] = path_down[u] + c;
      self(self, i, u);
    }
  };
  dfs(dfs, 1, 0);

  long long ans = 0;
  auto dfs1 = [&](auto &&self, int u, int p, long long dep) -> long long {
    // up + dep - path_up[u] ==> when rooted at u = [u]
    // ans = max(ans, [u] + (max_down in the subtree of u - path_down[u]))
    // then lca = cur node case ==> ans = max(ans, [u] + (v[0] - path_down[u]) +
    // (v[1] - path_down[u]))
    long long max_down = path_down[u];
    std::vector<long long> v;
    for (auto &[i, pr] : adj[u]) {
      if (i == p) {
        continue;
      }
      auto [c, d] = pr;
      v.push_back(self(self, i, u, dep + c));
      max_down = std::max(max_down, v.back());
    }
    long long _u_ = up + dep - path_up[u];
    ans = std::max(ans, _u_ + (max_down - path_down[u]));
    std::sort(v.rbegin(), v.rend());
    if (v.size() > 1) {
      ans = std::max(ans, _u_ + (v[0] - path_down[u]) + (v[1] - path_down[u]));
    }
    return max_down;
  };
  dfs1(dfs1, 1, 0, 0);

  int q;
  std::cin >> q;
  while (q--) {
    int x;
    std::cout << tot - ans << '\n';
  }
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 9 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44