Submission #914793

#	Time	Username	Problem	Language	Result	Execution time	Memory
914793		nima_aryan	Inside information (BOI21_servers)	C++17	5 / 100	196 ms	26564 KiB

servers

/**
 *    author:  NimaAryan
 *    created: 2024-01-22 15:04:53
**/
#include <bits/stdc++.h>

using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

template <typename T, class C = less<>>
using indexed_set = tree<T, null_type, C, rb_tree_tag,
      tree_order_statistics_node_update>;

#ifdef LOCAL
#include "algo/debug.h"
#endif

using i64 = long long;

struct Solver {
  int n;
  vector<vector<pair<int, int>>> adj;

  vector<vector<pair<int, int>>> qry1;
  vector<vector<int>> qry2;

  vector<int> siz;
  vector<bool> alive;

  vector<int> join;
  vector<int> leave;
  vector<int> reach;

  vector<int> ans;

  Solver(int n, int k) : n(n) {
    adj.resize(n);

    qry1.resize(n);
    qry2.resize(n);

    siz.resize(n);
    alive.assign(n, true);

    join.assign(n, -1);
    leave.assign(n, -1);
    reach.assign(n, -1);

    ans.resize(n - 1 + k);
  }

  void add_edge(int a, int b, int w) {
    adj[a].emplace_back(b, w);
    adj[b].emplace_back(a, w);
  }

  void add_query1(int a, int d, int t) {
    qry1[d].emplace_back(a, t);
  }
  void add_query2(int d, int t) {
    qry2[d].push_back(t);
  }

  void dfs(int v, int p = -1) {
    siz[v] = 1;
    for (auto [u, _] : adj[v]) {
      if (u != p && alive[u]) {
        dfs(u, v);
        siz[v] += siz[u];
      }
    }
    join[v] = leave[v] = reach[v] = -1;
  }
  int find_centroid(int v, int z, int p = -1) {
    for (auto [u, _] : adj[v]) {
      if (u != p && alive[u] && siz[u] > z / 2) {
        return find_centroid(u, z, v);
      }
    }
    return v;
  }

  void solve(int v = 0) {
    dfs(v);
    int c = find_centroid(v, siz[v]);

    {
      /* increasing */
      auto trav = [&](auto self, int x, int p) -> void {
        for (auto [y, z] : adj[x]) {
          if (y != p && alive[y] && reach[x] < z) {
            leave[y] = leave[x];
            reach[y] = z;
            self(self, y, x);
          }
        }
      };
      for (auto [u, w] : adj[c]) {
        if (alive[u]) {
          leave[u] = reach[u] = w;
          trav(trav, u, c);
        }
      }
    }
    {
      /* decreasing */
      auto trav = [&](auto self, int x, int w, int p) -> void {
        for (auto [y, z] : adj[x]) {
          if (y != p && alive[y] && w > z) {
            join[y] = join[x];
            self(self, y, z, x);
          }
        }
      };
      for (auto [u, w] : adj[c]) {
        if (alive[u]) {
          join[u] = w;
          trav(trav, u, w, c);
        }
      }
    }

    sort(adj[c].begin(), adj[c].end(), [&](auto p, auto q) {
      return p.second > q.second;
    });

    indexed_set<int> can;
    vector<int> comp;
    auto trav = [&](auto self, int x, int p) -> void {
      comp.push_back(x);
      for (auto [y, _] : adj[x]) {
        if (y != p && alive[y]) {
          self(self, y, x);
        }
      }
    };

    for (auto [u, _] : adj[c]) {
      if (alive[u]) {
        comp.clear();
        trav(trav, u, c);

        for (int d : comp) {
          for (auto [a, t] : qry1[d]) {
            if (ans[t]) {
              continue;
            }
            if (a == d) {
              ans[t] = -1;
              continue;
            }
            if (a == c) {
              if (join[d] != -1 && join[d] < t) {
                ans[t] = -1;
              } else {
                ans[t] = -2;
              }
              continue;
            }
            if (join[d] != -1 && leave[a] != -1 && join[d] < leave[a] &&
                reach[a] != -1 && reach[a] < t) {
              ans[t] = -1;
            } else {
              ans[t] = -2;
            }
          }
          for (int t : qry2[d]) {
            if (join[d] != -1 && join[d] < t) {
              ans[t] += can.order_of_key(t) + 1;
            }
          }
        }
        for (int x : comp) {
          if (reach[x] != -1) {
            can.insert(reach[x]);
          }
        }
      }
    }

    {
      int d = c;
      for (auto [a, t] : qry1[d]) {
        if (ans[t]) {
          continue;
        }
        if (a == d) {
          ans[t] = -1;
          continue;
        }
        if (reach[a] != -1 && reach[a] < t) {
          ans[t] = -1;
        } else {
          ans[t] = -2;
        }
      }
      for (int t : qry2[d]) {
        ans[t] += can.order_of_key(t) + 1;
      }
    }

    alive[c] = false;
    for (auto [u, _] : adj[c]) {
      if (alive[u]) {
        solve(u);
      }
    }
  }
};

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

  int n, k;
  cin >> n >> k;

  Solver t(n, k);
  for (int i = 0; i < n - 1 + k; ++i) {
    char op;
    cin >> op;
    if (op == 'S') {
      int a, b;
      cin >> a >> b;
      --a, --b;
      t.add_edge(a, b, i);
    } else if (op == 'Q') {
      int a, d;
      cin >> a >> d;
      --a, --d;
      t.add_query1(a, d, i);
    } else {
      int d;
      cin >> d;
      --d;
      t.add_query2(d, i);
    }
  }
  t.solve();

  for (int i = 0; i < n - 1 + k; ++i) {
    int res = t.ans[i];
    if (res) {
      if (res > 0) {
        cout << res << "\n";
      } else {
        cout << (res == -1 ? "yes" : "no") << "\n";
      }
    }
  }

  return 0;
}

• Subtask 1: 0 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 2.5 / 2.5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 0 / 17.5
• Subtask 12: 0 / 17.5