oj.uz

Submission #223872

# Submission time Handle Problem Language Result Execution time Memory
223872 2020-04-16T18:53:44 Z Bruteforceman Cat in a tree (BOI17_catinatree) C++11
100 / 100
 623 ms 39524 KB 
#include <bits/stdc++.h>
using namespace std;
using pii = pair <int, int>;
const int maxn = 2e5 + 10;
vector <int> g[maxn];
int dep[maxn];
bool done[maxn];
int n, D;
int anc[20][maxn];
const int logn = 19;
const int inf = 1e9 + 7;
int sub[maxn];

void flood(int x, int par, int dist) {
  if(dist == 0) return ;
  done[x] = true;
  for(auto i : g[x]) {
    if(i != par) {
      flood(i, x, dist - 1);
    }
  }
}
void dfs(int x, int par) {
  anc[0][x] = par == -1 ? 0 : par;
  for(int i = 1; i <= logn; i++) {
    anc[i][x] = anc[i - 1][anc[i - 1][x]];
  }
  for(auto i : g[x]) {
    if(i != par) {
      dep[i] = 1 + dep[x];
      dfs(i, x);
    }
  }
}
int lca(int x, int y) {
  if(dep[x] > dep[y]) swap(x, y);
  for(int i = logn; i >= 0; i--) {
    if(dep[y] - (1 << i) >= dep[x]) {
      y = anc[i][y];
    }
  }
  if(x == y) return x;
  for(int i = logn; i >= 0; i--) {
    if(anc[i][x] != anc[i][y]) {
      x = anc[i][x];
      y = anc[i][y];
    }
  }
  return anc[0][y];
}
int distance(int p, int q) {
  return dep[p] + dep[q] - 2 * dep[lca(p, q)];
}

int dad[maxn];
bool vis[maxn];
int near[maxn];

void subtree(int x, int par) {
  sub[x] = 1;
  for(auto i : g[x]) {
    if(vis[i]) continue;
    if(i != par) {
      subtree(i, x);
      sub[x] += sub[i];
    }
  }
}
int centroid(int x, int par, int range) {
  for(auto i : g[x]) {
    if(vis[i]) continue;
    if(i != par) {
      if(range < sub[i]) return centroid(i, x, range);
    }
  }
  return x;
}

int createTree(int x) {
  subtree(x, -1);
  x = centroid(x, -1, sub[x] / 2);
  vis[x] = true;
  near[x] = inf;
  for(auto i : g[x]) {
    if(!vis[i]) {
      dad[createTree(i)] = x;
    }
  }
  return x;
}
void add(int x) {
  int cur = x;
  while(cur != -1) {
    near[cur] = min(near[cur], distance(x, cur));
    cur = dad[cur];
  }
  return ;
}
int closest(int x) {
  int cur = x;
  int opt = inf;
  while(cur != -1) {
    opt = min(opt, distance(x, cur) + near[cur]);
    cur = dad[cur];
  }
  return opt;
}
int main() {
  ios_base :: sync_with_stdio (false);
  cin.tie(0);
  cin >> n >> D;
  for(int i = 1; i < n; i++) {
    int x;
    cin >> x;
    g[x].emplace_back(i);
    g[i].emplace_back(x);
  }
  dfs(0, -1);
  
//   cout << distance(0, 3) << endl;
    
  vector <pii> v;
  for(int i = 0; i < n; i++) {
    v.emplace_back(dep[i], i);
  }
  sort(v.begin(), v.end(), greater <pii> ());
  dad[createTree(0)] = -1;

  int ans = 0;
  for(auto i : v) {
    if(closest(i.second) < D) continue;
    add(i.second);
    ++ans;
  }
  cout << ans << endl;
  return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 5120 KB Output is correct
3 Correct 7 ms 5120 KB Output is correct
4 Correct 8 ms 5120 KB Output is correct
5 Correct 8 ms 5120 KB Output is correct
6 Correct 7 ms 5248 KB Output is correct
7 Correct 7 ms 5248 KB Output is correct
8 Correct 8 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 5248 KB Output is correct
11 Correct 7 ms 5120 KB Output is correct
12 Correct 9 ms 5120 KB Output is correct
13 Correct 7 ms 5120 KB Output is correct
14 Correct 7 ms 5248 KB Output is correct
15 Correct 7 ms 5120 KB Output is correct
16 Correct 8 ms 5248 KB Output is correct
17 Correct 8 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 5120 KB Output is correct
3 Correct 7 ms 5120 KB Output is correct
4 Correct 8 ms 5120 KB Output is correct
5 Correct 8 ms 5120 KB Output is correct
6 Correct 7 ms 5248 KB Output is correct
7 Correct 7 ms 5248 KB Output is correct
8 Correct 8 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 5248 KB Output is correct
11 Correct 7 ms 5120 KB Output is correct
12 Correct 9 ms 5120 KB Output is correct
13 Correct 7 ms 5120 KB Output is correct
14 Correct 7 ms 5248 KB Output is correct
15 Correct 7 ms 5120 KB Output is correct
16 Correct 8 ms 5248 KB Output is correct
17 Correct 8 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct
21 Correct 9 ms 5504 KB Output is correct
22 Correct 8 ms 5248 KB Output is correct
23 Correct 7 ms 5248 KB Output is correct
24 Correct 7 ms 5248 KB Output is correct
25 Correct 8 ms 5248 KB Output is correct
26 Correct 8 ms 5248 KB Output is correct
27 Correct 8 ms 5376 KB Output is correct
28 Correct 9 ms 5376 KB Output is correct
29 Correct 8 ms 5376 KB Output is correct
30 Correct 9 ms 5376 KB Output is correct
31 Correct 10 ms 5376 KB Output is correct
32 Correct 8 ms 5408 KB Output is correct
33 Correct 8 ms 5376 KB Output is correct
34 Correct 8 ms 5376 KB Output is correct
35 Correct 8 ms 5376 KB Output is correct
36 Correct 8 ms 5376 KB Output is correct
37 Correct 8 ms 5376 KB Output is correct
38 Correct 8 ms 5376 KB Output is correct
39 Correct 9 ms 5504 KB Output is correct
40 Correct 9 ms 5504 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 5120 KB Output is correct
3 Correct 7 ms 5120 KB Output is correct
4 Correct 8 ms 5120 KB Output is correct
5 Correct 8 ms 5120 KB Output is correct
6 Correct 7 ms 5248 KB Output is correct
7 Correct 7 ms 5248 KB Output is correct
8 Correct 8 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 5248 KB Output is correct
11 Correct 7 ms 5120 KB Output is correct
12 Correct 9 ms 5120 KB Output is correct
13 Correct 7 ms 5120 KB Output is correct
14 Correct 7 ms 5248 KB Output is correct
15 Correct 7 ms 5120 KB Output is correct
16 Correct 8 ms 5248 KB Output is correct
17 Correct 8 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 7 ms 5120 KB Output is correct
20 Correct 7 ms 5120 KB Output is correct
21 Correct 9 ms 5504 KB Output is correct
22 Correct 8 ms 5248 KB Output is correct
23 Correct 7 ms 5248 KB Output is correct
24 Correct 7 ms 5248 KB Output is correct
25 Correct 8 ms 5248 KB Output is correct
26 Correct 8 ms 5248 KB Output is correct
27 Correct 8 ms 5376 KB Output is correct
28 Correct 9 ms 5376 KB Output is correct
29 Correct 8 ms 5376 KB Output is correct
30 Correct 9 ms 5376 KB Output is correct
31 Correct 10 ms 5376 KB Output is correct
32 Correct 8 ms 5408 KB Output is correct
33 Correct 8 ms 5376 KB Output is correct
34 Correct 8 ms 5376 KB Output is correct
35 Correct 8 ms 5376 KB Output is correct
36 Correct 8 ms 5376 KB Output is correct
37 Correct 8 ms 5376 KB Output is correct
38 Correct 8 ms 5376 KB Output is correct
39 Correct 9 ms 5504 KB Output is correct
40 Correct 9 ms 5504 KB Output is correct
41 Correct 131 ms 31080 KB Output is correct
42 Correct 240 ms 19436 KB Output is correct
43 Correct 184 ms 19356 KB Output is correct
44 Correct 180 ms 19308 KB Output is correct
45 Correct 182 ms 19308 KB Output is correct
46 Correct 614 ms 33456 KB Output is correct
47 Correct 458 ms 33512 KB Output is correct
48 Correct 506 ms 33472 KB Output is correct
49 Correct 446 ms 33384 KB Output is correct
50 Correct 116 ms 19692 KB Output is correct
51 Correct 130 ms 19688 KB Output is correct
52 Correct 124 ms 19692 KB Output is correct
53 Correct 346 ms 33764 KB Output is correct
54 Correct 299 ms 33872 KB Output is correct
55 Correct 275 ms 33764 KB Output is correct
56 Correct 12 ms 5632 KB Output is correct
57 Correct 40 ms 9472 KB Output is correct
58 Correct 214 ms 24940 KB Output is correct
59 Correct 623 ms 39524 KB Output is correct
60 Correct 159 ms 32748 KB Output is correct
61 Correct 273 ms 31980 KB Output is correct