Submission #1159502

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159502		jotinha	Bitaro’s Party (JOI18_bitaro)	C++20	7 / 100	2106 ms	258892 KiB

bitaro

/**
 *  author:  Jotinha (ツ)
 *  created: 02-28-2025 11:09:44
**/
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif

const int maxn = 100005, sq = 318;
int tot[maxn], vis[maxn];
vector<int> g[maxn];
vector<pair<int, vector<int>>> qr[maxn];
pair<int, int> dp[maxn][sq];

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m, q;
  cin >> n >> m >> q;
  for(int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    --u, --v;
    g[u].emplace_back(v);
    g[v].emplace_back(u);
  }
  int t = 0;
  for(int i = 0; i < q; i++) {
    int u, k;
    cin >> u >> k;
    --u;
    vector<int> v(k);
    for(int& j : v) {
      cin >> j;
      --j;
    }
    qr[u].emplace_back(make_pair(t++, v));
    tot[u] += (int) v.size();
  }
  auto bfs = [&](int u) {
    vector<int> dist(n, -1);
    queue<int> qe;
    qe.emplace(u);
    dist[u] = 0;
    while(!qe.empty()) {
      auto v = qe.front();
      qe.pop();
      for(int nxt : g[v]) {
        if(nxt < v && dist[nxt] < dist[v] + 1) {
          dist[nxt] = dist[v] + 1;
          qe.push(nxt);
        }
      } 
    }
    return dist;
  };
  const int inf = 0x3f3f3f3f;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < sq; j++) {
      dp[i][j] = {-inf, -inf};
    }
  }
  function<void(int)> dfs = [&](int u) {
    if(vis[u]) {
      return;
    }
    set<pair<int, int>> wait { {0, u} };
    for(int nxt : g[u]) {
      if(nxt < u) {
        dfs(nxt);
        for(int i = 0; i < sq && dp[nxt][i].first >= 0; i++) {
          wait.insert({dp[nxt][i].first + 1, dp[nxt][i].second});
          if((int) wait.size() >= sq) {
            wait.erase(wait.begin());
          }
        }
      }
    }
    int te = (int) wait.size();
    for(int i = 0; i < te; i++) {
      auto [d, v] = *wait.rbegin();
      dp[u][i] = {d, v};
      wait.erase(--wait.end());
    }
    vis[u] = 1;
  };
  vector<int> ans(t, -1);
  for(int i = n - 1; i >= 0; i--) {
    if(tot[i] >= sq) {
      auto dist = bfs(i);
      multiset<int> ms(dist.begin(), dist.end());
      ms.insert(-1);
      for(int j = 0; j < qr[i].size(); j++) {
        for(int nxt : qr[i][j].second) {
          ms.erase(ms.find(dist[nxt]));
        }
        ans[qr[i][j].first] = *ms.rbegin();
        for(int nxt : qr[i][j].second) {
          ms.insert(dist[nxt]);
        }
      }
    } else {
      dfs(i);
      // cerr << i + 1 << '\n';
      // for(int j = 0; j < 5; j++) {
      //   cerr << dp[i][j].first << ' ' << dp[i][j].second + 1 << '\n';
      // }
      // cerr << "------------\n";
      for(int j = 0; j < sq; j++) {
        for(int k = 0; k < qr[i].size(); k++) {
          if(ans[qr[i][k].first] == -1) {
            int show = 1;
            for(int nxt : qr[i][k].second) {
              if(nxt == dp[i][j].second) {
                show = 0;
                break;
              }
            }
            if(show) {
              ans[qr[i][k].first] = dp[i][j].first;
            }
          }
        }
      }
    }
  }
  for(int x : ans) {
    cout << (x < 0 ? -1 : x)  << '\n';
  }
  return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86