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Submission #1037589

# Submission time Handle Problem Language Result Execution time Memory
1037589 2024-07-29T05:22:27 Z juicy Meetings 2 (JOI21_meetings2) C++17
100 / 100
 171 ms 40824 KB 
#include <bits/stdc++.h>

using namespace std;

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

const int N = 2e5 + 5, LG = 18;

int n;
int res[N], pr[LG][N], sz[N], dep[N];
vector<int> g[N];

void dfs(int u) {
  sz[u] = 1;
  for (int v : g[u]) {
    if (v != pr[0][u]) {
      pr[0][v] = u;
      dep[v] = dep[u] + 1;
      dfs(v);
      sz[u] += sz[v];
    }
  }
}

int findCen(int u, int p) {
  for (int v : g[u]) {
    if (v != p && sz[v] * 2 > n) {
      return findCen(v, u);
    }
  }
  return u;
}

int lca(int u, int v) {
  if (dep[u] < dep[v]) {
    swap(u, v);
  }
  for (int j = LG - 1; ~j; --j) {
    if (dep[u] - (1 << j) >= dep[v]) {
      u = pr[j][u];
    }
  }
  if (u == v) {
    return u;
  }
  for (int j = LG - 1; ~j; --j) {
    if (pr[j][u] ^ pr[j][v]) {
      u = pr[j][u], v = pr[j][v];
    }
  }
  return pr[0][u];
}

int dis(int u, int v) {
  return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}

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

  cin >> n;
  for (int i = 1; i < n; ++i) {
    int u, v; cin >> u >> v;
    g[u].push_back(v);
    g[v].push_back(u);
  }  
  dfs(1);
  int c = findCen(1, 1);
  pr[0][c] = 0;
  dfs(c);
  for (int j = 1; j < LG; ++j) {
    for (int i = 1; i <= n; ++i) {
      pr[j][i] = pr[j - 1][pr[j - 1][i]];
    }
  }
  array<int, 3> best{0, c, c};
  vector<int> cands;
  for (int i = 1; i <= n; ++i) {
    if (i ^ c) {
      cands.push_back(i);
    }
  }
  sort(cands.begin(), cands.end(), [&](int i, int j) {
    return sz[i] > sz[j];
  });
  for (int i = n / 2, j = 0; i > 0; --i) {
    while (j < cands.size() && sz[cands[j]] == i) {
      int u = cands[j], a = best[1], b = best[2];
      best = max({best, {dis(u, a), a, u}, {dis(u, b), b, u}});
      ++j;
    } 
    res[i * 2] = best[0];
  }
  for (int i = 1; i <= n; ++i) {
    cout << res[i] + 1 << "\n";
  }
  return 0;
}

Compilation message

meetings2.cpp: In function 'int main()':
meetings2.cpp:91:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |     while (j < cands.size() && sz[cands[j]] == i) {
      |            ~~^~~~~~~~~~~~~~

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 21084 KB Output is correct
2 Correct 3 ms 21160 KB Output is correct
3 Correct 2 ms 21084 KB Output is correct
4 Correct 2 ms 21084 KB Output is correct
5 Correct 2 ms 21132 KB Output is correct
6 Correct 2 ms 21084 KB Output is correct
7 Correct 2 ms 21084 KB Output is correct
8 Correct 3 ms 21084 KB Output is correct
9 Correct 2 ms 21084 KB Output is correct
10 Correct 3 ms 21084 KB Output is correct
11 Correct 3 ms 21084 KB Output is correct
12 Correct 3 ms 21084 KB Output is correct
13 Correct 2 ms 21084 KB Output is correct
14 Correct 2 ms 21080 KB Output is correct
15 Correct 2 ms 21084 KB Output is correct
16 Correct 2 ms 21084 KB Output is correct
17 Correct 3 ms 21084 KB Output is correct
18 Correct 2 ms 21084 KB Output is correct
19 Correct 2 ms 21084 KB Output is correct
20 Correct 2 ms 21084 KB Output is correct
21 Correct 3 ms 21084 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 21084 KB Output is correct
2 Correct 3 ms 21160 KB Output is correct
3 Correct 2 ms 21084 KB Output is correct
4 Correct 2 ms 21084 KB Output is correct
5 Correct 2 ms 21132 KB Output is correct
6 Correct 2 ms 21084 KB Output is correct
7 Correct 2 ms 21084 KB Output is correct
8 Correct 3 ms 21084 KB Output is correct
9 Correct 2 ms 21084 KB Output is correct
10 Correct 3 ms 21084 KB Output is correct
11 Correct 3 ms 21084 KB Output is correct
12 Correct 3 ms 21084 KB Output is correct
13 Correct 2 ms 21084 KB Output is correct
14 Correct 2 ms 21080 KB Output is correct
15 Correct 2 ms 21084 KB Output is correct
16 Correct 2 ms 21084 KB Output is correct
17 Correct 3 ms 21084 KB Output is correct
18 Correct 2 ms 21084 KB Output is correct
19 Correct 2 ms 21084 KB Output is correct
20 Correct 2 ms 21084 KB Output is correct
21 Correct 3 ms 21084 KB Output is correct
22 Correct 4 ms 21592 KB Output is correct
23 Correct 4 ms 21340 KB Output is correct
24 Correct 4 ms 21268 KB Output is correct
25 Correct 4 ms 21232 KB Output is correct
26 Correct 5 ms 21340 KB Output is correct
27 Correct 4 ms 21340 KB Output is correct
28 Correct 4 ms 21340 KB Output is correct
29 Correct 4 ms 21340 KB Output is correct
30 Correct 4 ms 21340 KB Output is correct
31 Correct 5 ms 21592 KB Output is correct
32 Correct 4 ms 21340 KB Output is correct
33 Correct 5 ms 21340 KB Output is correct
34 Correct 4 ms 21372 KB Output is correct
35 Correct 3 ms 21340 KB Output is correct
36 Correct 4 ms 21340 KB Output is correct
37 Correct 3 ms 21336 KB Output is correct
38 Correct 4 ms 21400 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 21084 KB Output is correct
2 Correct 3 ms 21160 KB Output is correct
3 Correct 2 ms 21084 KB Output is correct
4 Correct 2 ms 21084 KB Output is correct
5 Correct 2 ms 21132 KB Output is correct
6 Correct 2 ms 21084 KB Output is correct
7 Correct 2 ms 21084 KB Output is correct
8 Correct 3 ms 21084 KB Output is correct
9 Correct 2 ms 21084 KB Output is correct
10 Correct 3 ms 21084 KB Output is correct
11 Correct 3 ms 21084 KB Output is correct
12 Correct 3 ms 21084 KB Output is correct
13 Correct 2 ms 21084 KB Output is correct
14 Correct 2 ms 21080 KB Output is correct
15 Correct 2 ms 21084 KB Output is correct
16 Correct 2 ms 21084 KB Output is correct
17 Correct 3 ms 21084 KB Output is correct
18 Correct 2 ms 21084 KB Output is correct
19 Correct 2 ms 21084 KB Output is correct
20 Correct 2 ms 21084 KB Output is correct
21 Correct 3 ms 21084 KB Output is correct
22 Correct 4 ms 21592 KB Output is correct
23 Correct 4 ms 21340 KB Output is correct
24 Correct 4 ms 21268 KB Output is correct
25 Correct 4 ms 21232 KB Output is correct
26 Correct 5 ms 21340 KB Output is correct
27 Correct 4 ms 21340 KB Output is correct
28 Correct 4 ms 21340 KB Output is correct
29 Correct 4 ms 21340 KB Output is correct
30 Correct 4 ms 21340 KB Output is correct
31 Correct 5 ms 21592 KB Output is correct
32 Correct 4 ms 21340 KB Output is correct
33 Correct 5 ms 21340 KB Output is correct
34 Correct 4 ms 21372 KB Output is correct
35 Correct 3 ms 21340 KB Output is correct
36 Correct 4 ms 21340 KB Output is correct
37 Correct 3 ms 21336 KB Output is correct
38 Correct 4 ms 21400 KB Output is correct
39 Correct 91 ms 31556 KB Output is correct
40 Correct 113 ms 31436 KB Output is correct
41 Correct 93 ms 31688 KB Output is correct
42 Correct 91 ms 31696 KB Output is correct
43 Correct 97 ms 31780 KB Output is correct
44 Correct 93 ms 31692 KB Output is correct
45 Correct 171 ms 36548 KB Output is correct
46 Correct 119 ms 40824 KB Output is correct
47 Correct 78 ms 32132 KB Output is correct
48 Correct 87 ms 32300 KB Output is correct
49 Correct 123 ms 32484 KB Output is correct
50 Correct 73 ms 32328 KB Output is correct
51 Correct 96 ms 39748 KB Output is correct