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Submission #788624

# Submission time Handle Problem Language Result Execution time Memory
788624 2023-07-20T12:20:16 Z WLZ Spring cleaning (CEOI20_cleaning) C++17
100 / 100
 146 ms 31220 KB 
#include <bits/stdc++.h>
using namespace std;
 
int max_log, dfs_cnt = 0, e = 0;
vector< vector<int> > g, up, aux;
vector<int> dfs_in, dfs_out, d, s, leaves;
vector<bool> critical;

void dfs(int u, int p) {
  up[u][0] = p;
  dfs_in[u] = dfs_cnt++;
  for (int i = 1; i <= max_log; i++) up[u][i] = up[up[u][i - 1]][i - 1];
  for (auto& v : g[u]) {
    if (v == p) continue;
    d[v] = d[u] + 1;
    dfs(v, u);
    leaves[u] += leaves[v];
  }
  dfs_out[u] = dfs_cnt;
  if ((int) g[u].size() == 1) leaves[u]++;  
}

void dfs2(int u, int p) {
  if (leaves[u] % 2 == 0) e++, s[u]++;
  for (auto& v : g[u]) {
    if (v != p) {
      s[v] += s[u];
      dfs2(v, u);
    }
  }
}

int dfs3(int u, int p, int &ans) {
  int cnt = 0;
  for (auto& v : aux[u]) {
    cnt += dfs3(v, u, ans);
  }
  if (critical[u]) cnt++;
  if (cnt % 2 == 1) {
    ans += d[u] - d[p] - 2 * (s[u] - s[p]);
  }
  return cnt;
}

bool is_anc(int u, int v) {
  return dfs_in[u] <= dfs_in[v] && dfs_out[u] >= dfs_out[v];
}

int lca(int u, int v) {
  if (is_anc(u, v)) return u;
  if (is_anc(v, u)) return v;
  for (int i = max_log; i >= 0; i--) {
    if (!is_anc(up[u][i], v)) u = up[u][i];
  }
  return up[u][0];
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, q;
  cin >> n >> q;
  g.resize(n + 1);
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  int r = 1;
  while ((int) g[r].size() == 1) r++;
  max_log = ceil(log2(n));
  up.assign(n + 1, vector<int>(max_log + 1));
  dfs_in.resize(n + 1); dfs_out.resize(n + 1);
  d.assign(n + 1, 0);
  leaves.assign(n + 1, 0);
  d[r] = 1;
  dfs(r, r);
  s.assign(n + 1, 0);
  dfs2(r, -1);
  critical.assign(n + 1, false);
  aux.resize(n + 1);
  while (q--) {
    int d;
    cin >> d;
    map<int, int> mp;
    for (int i = 0; i < d; i++) {
      int x;
      cin >> x;
      mp[x]++;
    }
    vector<int> v;
    for (auto& p : mp) {
      if ((int) g[p.first].size() == 1 && p.second % 2 == 0) v.push_back(p.first);
      if ((int) g[p.first].size() > 1 && p.second % 2 == 1) v.push_back(p.first);
    }
    for (auto& x : v) critical[x] = true;
    sort(v.begin(), v.end(), [&](int a, int b) {
      return dfs_in[a] < dfs_in[b];
    });
    for (int i = 1, sz = (int) v.size(); i < sz; i++) {
      v.push_back(lca(v[i - 1], v[i]));
    }
    sort(v.begin(), v.end(), [&](int a, int b) {
      return dfs_in[a] < dfs_in[b];
    });
    v.erase(unique(v.begin(), v.end()), v.end());
    if (v.empty()) {
      if (leaves[r] % 2 == 0) cout << n + d + e - 2 << '\n';
      else cout << -1 << '\n';
      continue;
    }
    vector<int> st = {v[0]};
    for (int i = 1; i < (int) v.size(); i++) {
      while (!is_anc(st.back(), v[i])) st.pop_back();
      aux[st.back()].push_back(v[i]);
      st.push_back(v[i]);
    }
    int tmp = e;
    if ((leaves[r] + dfs3(st[0], 0, tmp)) % 2 == 0) {
      cout << n + d + tmp - 2 << '\n';
    } else {
      cout << -1 << '\n';
    }
    for (auto& x : v) {
      aux[x].clear();
      critical[x] = false;
    }
  }
  return 0;
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 41 ms 5388 KB Output is correct

Subtask #2
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 1420 KB Output is correct
2 Correct 11 ms 1384 KB Output is correct
3 Correct 51 ms 21676 KB Output is correct
4 Correct 61 ms 18492 KB Output is correct
5 Correct 80 ms 25120 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 2356 KB Output is correct
2 Correct 15 ms 2284 KB Output is correct
3 Correct 58 ms 29164 KB Output is correct
4 Correct 93 ms 31148 KB Output is correct
5 Correct 53 ms 26352 KB Output is correct

Subtask #4
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 5972 KB Output is correct
2 Correct 19 ms 4948 KB Output is correct
3 Correct 9 ms 4564 KB Output is correct
4 Correct 10 ms 5076 KB Output is correct
5 Correct 11 ms 5204 KB Output is correct
6 Correct 28 ms 5792 KB Output is correct

Subtask #5
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 14952 KB Output is correct
2 Correct 66 ms 15136 KB Output is correct
3 Correct 49 ms 8156 KB Output is correct
4 Correct 62 ms 15064 KB Output is correct
5 Correct 63 ms 15120 KB Output is correct

Subtask #6
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 86 ms 22764 KB Output is correct
2 Correct 118 ms 25452 KB Output is correct
3 Correct 131 ms 25480 KB Output is correct
4 Correct 109 ms 24908 KB Output is correct

Subtask #7
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 41 ms 5388 KB Output is correct
3 Correct 11 ms 1420 KB Output is correct
4 Correct 11 ms 1384 KB Output is correct
5 Correct 51 ms 21676 KB Output is correct
6 Correct 61 ms 18492 KB Output is correct
7 Correct 80 ms 25120 KB Output is correct
8 Correct 14 ms 2356 KB Output is correct
9 Correct 15 ms 2284 KB Output is correct
10 Correct 58 ms 29164 KB Output is correct
11 Correct 93 ms 31148 KB Output is correct
12 Correct 53 ms 26352 KB Output is correct
13 Correct 30 ms 5972 KB Output is correct
14 Correct 19 ms 4948 KB Output is correct
15 Correct 9 ms 4564 KB Output is correct
16 Correct 10 ms 5076 KB Output is correct
17 Correct 11 ms 5204 KB Output is correct
18 Correct 28 ms 5792 KB Output is correct
19 Correct 69 ms 14952 KB Output is correct
20 Correct 66 ms 15136 KB Output is correct
21 Correct 49 ms 8156 KB Output is correct
22 Correct 62 ms 15064 KB Output is correct
23 Correct 63 ms 15120 KB Output is correct
24 Correct 86 ms 22764 KB Output is correct
25 Correct 118 ms 25452 KB Output is correct
26 Correct 131 ms 25480 KB Output is correct
27 Correct 109 ms 24908 KB Output is correct
28 Correct 76 ms 13936 KB Output is correct
29 Correct 119 ms 25832 KB Output is correct
30 Correct 99 ms 25152 KB Output is correct
31 Correct 81 ms 31220 KB Output is correct
32 Correct 68 ms 15132 KB Output is correct
33 Correct 102 ms 21484 KB Output is correct
34 Correct 144 ms 26528 KB Output is correct
35 Correct 146 ms 26344 KB Output is correct