oj.uz

답안 #559311

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
559311 2022-05-09T15:15:25 Z Sweezy Cat in a tree (BOI17_catinatree) C++17
100 / 100
 927 ms 69140 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, vis[N];

void sizes(int v, int p) {
  mdist[v] = inf;
  vis[v] = 0;
  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 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 (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 (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

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 7 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 6 ms 11220 KB Output is correct
5 Correct 6 ms 11348 KB Output is correct
6 Correct 7 ms 11220 KB Output is correct
7 Correct 7 ms 11336 KB Output is correct
8 Correct 7 ms 11220 KB Output is correct
9 Correct 6 ms 11220 KB Output is correct
10 Correct 6 ms 11220 KB Output is correct
11 Correct 6 ms 11220 KB Output is correct
12 Correct 6 ms 11220 KB Output is correct
13 Correct 6 ms 11220 KB Output is correct
14 Correct 7 ms 11220 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 7 ms 11272 KB Output is correct
17 Correct 7 ms 11220 KB Output is correct
18 Correct 6 ms 11220 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11220 KB Output is correct

Subtask #2
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 7 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 6 ms 11220 KB Output is correct
5 Correct 6 ms 11348 KB Output is correct
6 Correct 7 ms 11220 KB Output is correct
7 Correct 7 ms 11336 KB Output is correct
8 Correct 7 ms 11220 KB Output is correct
9 Correct 6 ms 11220 KB Output is correct
10 Correct 6 ms 11220 KB Output is correct
11 Correct 6 ms 11220 KB Output is correct
12 Correct 6 ms 11220 KB Output is correct
13 Correct 6 ms 11220 KB Output is correct
14 Correct 7 ms 11220 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 7 ms 11272 KB Output is correct
17 Correct 7 ms 11220 KB Output is correct
18 Correct 6 ms 11220 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11220 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 11348 KB Output is correct
24 Correct 7 ms 11348 KB Output is correct
25 Correct 7 ms 11348 KB Output is correct
26 Correct 7 ms 11396 KB Output is correct
27 Correct 7 ms 11348 KB Output is correct
28 Correct 9 ms 11476 KB Output is correct
29 Correct 7 ms 11476 KB Output is correct
30 Correct 8 ms 11448 KB Output is correct
31 Correct 7 ms 11476 KB Output is correct
32 Correct 7 ms 11476 KB Output is correct
33 Correct 7 ms 11476 KB Output is correct
34 Correct 7 ms 11516 KB Output is correct
35 Correct 8 ms 11440 KB Output is correct
36 Correct 7 ms 11520 KB Output is correct
37 Correct 7 ms 11456 KB Output is correct
38 Correct 8 ms 11476 KB Output is correct
39 Correct 8 ms 11476 KB Output is correct
40 Correct 9 ms 11604 KB Output is correct

Subtask #3
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 11220 KB Output is correct
2 Correct 7 ms 11220 KB Output is correct
3 Correct 6 ms 11220 KB Output is correct
4 Correct 6 ms 11220 KB Output is correct
5 Correct 6 ms 11348 KB Output is correct
6 Correct 7 ms 11220 KB Output is correct
7 Correct 7 ms 11336 KB Output is correct
8 Correct 7 ms 11220 KB Output is correct
9 Correct 6 ms 11220 KB Output is correct
10 Correct 6 ms 11220 KB Output is correct
11 Correct 6 ms 11220 KB Output is correct
12 Correct 6 ms 11220 KB Output is correct
13 Correct 6 ms 11220 KB Output is correct
14 Correct 7 ms 11220 KB Output is correct
15 Correct 6 ms 11220 KB Output is correct
16 Correct 7 ms 11272 KB Output is correct
17 Correct 7 ms 11220 KB Output is correct
18 Correct 6 ms 11220 KB Output is correct
19 Correct 6 ms 11220 KB Output is correct
20 Correct 6 ms 11220 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 11348 KB Output is correct
24 Correct 7 ms 11348 KB Output is correct
25 Correct 7 ms 11348 KB Output is correct
26 Correct 7 ms 11396 KB Output is correct
27 Correct 7 ms 11348 KB Output is correct
28 Correct 9 ms 11476 KB Output is correct
29 Correct 7 ms 11476 KB Output is correct
30 Correct 8 ms 11448 KB Output is correct
31 Correct 7 ms 11476 KB Output is correct
32 Correct 7 ms 11476 KB Output is correct
33 Correct 7 ms 11476 KB Output is correct
34 Correct 7 ms 11516 KB Output is correct
35 Correct 8 ms 11440 KB Output is correct
36 Correct 7 ms 11520 KB Output is correct
37 Correct 7 ms 11456 KB Output is correct
38 Correct 8 ms 11476 KB Output is correct
39 Correct 8 ms 11476 KB Output is correct
40 Correct 9 ms 11604 KB Output is correct
41 Correct 143 ms 29768 KB Output is correct
42 Correct 354 ms 28300 KB Output is correct
43 Correct 346 ms 28864 KB Output is correct
44 Correct 290 ms 28612 KB Output is correct
45 Correct 341 ms 28544 KB Output is correct
46 Correct 909 ms 45772 KB Output is correct
47 Correct 833 ms 46796 KB Output is correct
48 Correct 900 ms 47040 KB Output is correct
49 Correct 927 ms 47132 KB Output is correct
50 Correct 187 ms 24864 KB Output is correct
51 Correct 186 ms 25280 KB Output is correct
52 Correct 183 ms 25132 KB Output is correct
53 Correct 541 ms 40052 KB Output is correct
54 Correct 518 ms 39592 KB Output is correct
55 Correct 503 ms 39624 KB Output is correct
56 Correct 9 ms 11860 KB Output is correct
57 Correct 38 ms 16752 KB Output is correct
58 Correct 199 ms 40380 KB Output is correct
59 Correct 868 ms 69140 KB Output is correct
60 Correct 145 ms 30268 KB Output is correct
61 Correct 326 ms 37012 KB Output is correct