oj.uz

Submission #559305

# Submission time Handle Problem Language Result Execution time Memory
559305 2022-05-09T15:13:20 Z Sweezy Cat in a tree (BOI17_catinatree) C++17
51 / 100
 1000 ms 47124 KB 
#include <bits/stdc++.h>
 
using namespace std;
// #define int long long

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

#define all(a) (a).begin(), (a).end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define reps(i, s, n) for (int i = s; i < (n); ++i)
#define pb push_back
#define sz(a) (int) (a.size())

const int N = 2e5 + 5;
const int inf = 1e9;

vector<int> g[N];
vector<pair<int, int>> centroids[N];
int s[N], mdist[N], used[N], res, d, m;

void sizes(int v, int p) {
  mdist[v] = inf;
  s[v] = 1;
  for (auto &u : g[v]) {
    if (u != p && !used[u]) {
      sizes(u, v);
      s[v] += s[u];
    }
  }
}

int centroid(int v, int p, int n) {
  for (auto &u : g[v]) {
    if (u != p && !used[u] && s[u] > n / 2) {
      return centroid(u, v, n);
    } 
  }
  return v;
}

int vis[N], dis[N], q[N], from, to, vs[N];

void decomposition1(int v) {
  used[v] = 1;
  sizes(v, -1);

  m = 0;
  from = 0;
  to = 1;
  dis[v] = 0;
  q[0] = v;
  while (from != to) {
    int ver = q[from++];
    vs[m++] = ver;
    centroids[ver].emplace_back(v, dis[ver]);
    vis[ver] = 1;
    for (auto &u : g[ver]) {
      if (!used[u] && !vis[u]) {
        dis[u] = dis[ver] + 1;
        q[to++] = u;
        vis[u] = 1;
      }
    }
  }

  for (int i = 0; i < m; i++) {
    vis[vs[i]] = 0;
  }

  for (auto &u : g[v]) {
    if (!used[u]) {
      decomposition1(centroid(u, v, s[u]));
    }
  }
}


void decomposition2(int v) {
  used[v] = 1;
  sizes(v, -1);

  m = 0;
  from = 0;
  to = 1;
  dis[v] = 0;
  q[0] = v;
  while (from != to) {
    int ver = q[from++];
    vs[m++] = ver;
    vis[ver] = 1;
    for (auto &u : g[ver]) {
      if (!used[u] && !vis[u]) {
        dis[u] = dis[ver] + 1;
        q[to++] = u;
        vis[u] = 1;
      }
    }
  }

  auto can = [&] (int ver) -> bool {
    for (auto &[centroid, dist_to_centroid] : centroids[ver]) {
      if (dist_to_centroid + mdist[centroid] < d) {
        return false;
      }
    }
    return true;
  };

  int r = m, cnt = 0;
  rep(l, m) {
    while (r - 1 >= l && dis[vs[r - 1]] >= max(dis[vs[l]], d - dis[vs[l]])) {
      r--;
      int ver = vs[r];
      if (can(ver)) {
        cnt++;
        for (auto &[centroid, dist_to_centroid] : centroids[ver]) {
          mdist[centroid] = min(mdist[centroid], dist_to_centroid);
        }
      }
    }
    if (l == r) {
      res = max(res, cnt);
      break;
    } else {
      res = max(res, cnt + can(vs[l]));
    }
  }

  for (int i = 0; i < m; i++) {
    vis[vs[i]] = 0;
  }

  for (auto &u : g[v]) {
    if (!used[u]) {
      decomposition2(centroid(u, v, s[u]));
    }
  }
}

void solve() {
  fill(mdist, mdist + N, inf);

  int n;
  cin >> n >> d;
 
  if (d > n - 1) {
    cout << 1;
    return;
  }
 
  if (d == 0) {
    cout << n;
    return;
  }
 
  reps(i, 1, n) {
    int p;
    cin >> p;
    g[p].push_back(i);
    g[i].push_back(p);
  }
  
  sizes(0, -1);
  decomposition1(centroid(0, -1, n));

  fill(used, used + N, 0);
  sizes(0, -1);
  decomposition2(centroid(0, -1, n));

  cout << res;
}
 
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  solve();
  return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 8 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 7 ms 11220 KB Output is correct
5 Correct 8 ms 11220 KB Output is correct
6 Correct 6 ms 11220 KB Output is correct
7 Correct 6 ms 11220 KB Output is correct
8 Correct 7 ms 11348 KB Output is correct
9 Correct 8 ms 11220 KB Output is correct
10 Correct 7 ms 11220 KB Output is correct
11 Correct 7 ms 11220 KB Output is correct
12 Correct 7 ms 11220 KB Output is correct
13 Correct 7 ms 11220 KB Output is correct
14 Correct 7 ms 11304 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 6 ms 11220 KB Output is correct
17 Correct 7 ms 11224 KB Output is correct
18 Correct 6 ms 11400 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11216 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 8 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 7 ms 11220 KB Output is correct
5 Correct 8 ms 11220 KB Output is correct
6 Correct 6 ms 11220 KB Output is correct
7 Correct 6 ms 11220 KB Output is correct
8 Correct 7 ms 11348 KB Output is correct
9 Correct 8 ms 11220 KB Output is correct
10 Correct 7 ms 11220 KB Output is correct
11 Correct 7 ms 11220 KB Output is correct
12 Correct 7 ms 11220 KB Output is correct
13 Correct 7 ms 11220 KB Output is correct
14 Correct 7 ms 11304 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 6 ms 11220 KB Output is correct
17 Correct 7 ms 11224 KB Output is correct
18 Correct 6 ms 11400 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11216 KB Output is correct
21 Correct 8 ms 11604 KB Output is correct
22 Correct 7 ms 11348 KB Output is correct
23 Correct 6 ms 11260 KB Output is correct
24 Correct 8 ms 11348 KB Output is correct
25 Correct 9 ms 11400 KB Output is correct
26 Correct 7 ms 11348 KB Output is correct
27 Correct 8 ms 11348 KB Output is correct
28 Correct 8 ms 11476 KB Output is correct
29 Correct 8 ms 11544 KB Output is correct
30 Correct 8 ms 11476 KB Output is correct
31 Correct 7 ms 11448 KB Output is correct
32 Correct 7 ms 11476 KB Output is correct
33 Correct 7 ms 11492 KB Output is correct
34 Correct 8 ms 11476 KB Output is correct
35 Correct 7 ms 11476 KB Output is correct
36 Correct 7 ms 11476 KB Output is correct
37 Correct 8 ms 11476 KB Output is correct
38 Correct 11 ms 11476 KB Output is correct
39 Correct 8 ms 11524 KB Output is correct
40 Correct 10 ms 11568 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 8 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 7 ms 11220 KB Output is correct
5 Correct 8 ms 11220 KB Output is correct
6 Correct 6 ms 11220 KB Output is correct
7 Correct 6 ms 11220 KB Output is correct
8 Correct 7 ms 11348 KB Output is correct
9 Correct 8 ms 11220 KB Output is correct
10 Correct 7 ms 11220 KB Output is correct
11 Correct 7 ms 11220 KB Output is correct
12 Correct 7 ms 11220 KB Output is correct
13 Correct 7 ms 11220 KB Output is correct
14 Correct 7 ms 11304 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 6 ms 11220 KB Output is correct
17 Correct 7 ms 11224 KB Output is correct
18 Correct 6 ms 11400 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11216 KB Output is correct
21 Correct 8 ms 11604 KB Output is correct
22 Correct 7 ms 11348 KB Output is correct
23 Correct 6 ms 11260 KB Output is correct
24 Correct 8 ms 11348 KB Output is correct
25 Correct 9 ms 11400 KB Output is correct
26 Correct 7 ms 11348 KB Output is correct
27 Correct 8 ms 11348 KB Output is correct
28 Correct 8 ms 11476 KB Output is correct
29 Correct 8 ms 11544 KB Output is correct
30 Correct 8 ms 11476 KB Output is correct
31 Correct 7 ms 11448 KB Output is correct
32 Correct 7 ms 11476 KB Output is correct
33 Correct 7 ms 11492 KB Output is correct
34 Correct 8 ms 11476 KB Output is correct
35 Correct 7 ms 11476 KB Output is correct
36 Correct 7 ms 11476 KB Output is correct
37 Correct 8 ms 11476 KB Output is correct
38 Correct 11 ms 11476 KB Output is correct
39 Correct 8 ms 11524 KB Output is correct
40 Correct 10 ms 11568 KB Output is correct
41 Correct 146 ms 29652 KB Output is correct
42 Correct 408 ms 28472 KB Output is correct
43 Correct 298 ms 28864 KB Output is correct
44 Correct 306 ms 28620 KB Output is correct
45 Correct 327 ms 28472 KB Output is correct
46 Correct 957 ms 46040 KB Output is correct
47 Correct 838 ms 46748 KB Output is correct
48 Correct 985 ms 46920 KB Output is correct
49 Execution timed out 1022 ms 47124 KB Time limit exceeded
50 Halted 0 ms 0 KB -