Submission #646007

#	Time	Username	Problem	Language	Result	Execution time	Memory
646007		Alex_tz307	Paths (RMI21_paths)	C++17	100 / 100	449 ms	35220 KiB

Main

#include <bits/stdc++.h>

using namespace std;

const int kN = 1e5;
int n, k;
int64_t sumK, sol[1 + kN];
pair<int64_t, int> dmax[1 + kN];
vector<pair<int, int>> g[1 + kN];
set<pair<int64_t, int>> paths[1 + kN];
multiset<int64_t> low, big;

void fix() {
  while ((int)big.size() < k && !low.empty()) {
    auto it = --low.end();
    big.emplace(*it);
    sumK += *it;
    low.erase(it);
  }

  if (low.empty() || big.empty()) {
    return;
  }

  int64_t last = *(--low.end()), first = *big.begin();
  while (first < last) {
    big.erase(big.begin());
    low.erase(--low.end());
    low.emplace(first);
    sumK -= first;
    big.emplace(last);
    sumK += last;
    last = *(--low.end());
    first = *big.begin();
  }
}

void add(int64_t x) {
  if ((int)big.size() < k) {
    big.emplace(x);
    sumK += x;
  } else {
    low.emplace(x);
    fix();
  }
}

void rem(int64_t x) {
  if (low.count(x)) {
    low.erase(low.find(x));
  } else {
    big.erase(big.find(x));
    sumK -= x;
    fix();
  }
}

void dfs1(int u, int par) {
  for (auto it : g[u]) {
    int v, w;
    tie(v, w) = it;

    if (v != par) {
      dfs1(v, u);

      if (paths[v].empty()) {
        paths[u].emplace(w, v);
      } else {
        paths[u].emplace((--paths[v].end())->first + w, v);
      }
    }
  }
}

void dfs2(int u, int par) {
  sol[u] = sumK;

  for (auto it : g[u]) {
    int v, w;
    tie(v, w) = it;

    if (v != par) {
      auto it1 = --paths[u].end();
      pair<int64_t, int> path1, removed{-1, -1};

      if (it1->second == v) {
        if ((int)paths[u].size() == 1) {
          path1 = {w, u};
        } else {
          auto it2 = --it1;
          path1 = {it2->first + w, u};
          removed = *it2;
        }
      } else {
        path1 = {it1->first + w, u};
        removed = *it1;
      }

      paths[v].emplace(path1);
      add(path1.first);
      if (removed.first != -1) {
        rem(removed.first);
      }

      pair<int64_t, int> path2{dmax[v].first + w, v};
      rem(path2.first);
      paths[v].emplace(dmax[v]);
      add(dmax[v].first);

      dfs2(v, u);

      rem(path1.first);
      if (removed.first != -1) {
        add(removed.first);
      }

      add(path2.first);
      rem(dmax[v].first);
    }
  }
}

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

  cin >> n >> k;
  for (int i = 1; i < n; ++i) {
    int u, v, w;
    cin >> u >> v >> w;
    g[u].emplace_back(v, w);
    g[v].emplace_back(u, w);
  }

  dfs1(1, 0);

  for (int i = 1; i <= n; ++i) {
    if (!paths[i].empty()) {
      auto it = *(--paths[i].end());
      dmax[i] = it;
      if (i != 1) {
        paths[i].erase(it);
      }
    }

    for (auto it : paths[i]) {
      add(it.first);
    }

    while ((int)paths[i].size() > 2) {
      paths[i].erase(paths[i].begin());
    }
  }

  dfs2(1, 0);

  for (int i = 1; i <= n; ++i) {
    cout << sol[i] << '\n';
  }

  return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 12 / 12
• Subtask 6: 32 / 32