oj.uz

Submission #577218

# Submission time Handle Problem Language Result Execution time Memory
577218 2022-06-14T09:33:31 Z Sam_a17 Cat in a tree (BOI17_catinatree) C++14
100 / 100
 500 ms 43588 KB 
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount

#define pb push_back
#define popf pop_front
#define popb pop_back

void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();

  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2e5 + 10, LOG = 22;
int n, m, sz[N], compSize, p[N], best[N], up[N][LOG], depth[N];
vector<int> adj[N];
bool used[N];

void dfs_lca(int node, int parent) {
  for(auto i: adj[node]) {
    if(i == parent) continue;
    up[i][0] = node;
    for(int j = 1; j < LOG; j++) {
      up[i][j] = up[up[i][j - 1]][j - 1];
    }
    depth[i] = depth[node] + 1;
    dfs_lca(i, node);
  }
}

int lca(int a, int b) {
  if(a == b) {
    return a;
  }

  if(depth[a] < depth[b]) {
    swap(a, b);
  }

  int delta = depth[a] - depth[b];

  for(int i = 0; i < LOG; i++) {
    if(delta & (1 << i)) {
      a = up[a][i];
    }
  }

  if(a == b) {
    return a;
  }

  for(int i = LOG - 1; i >= 0; i--) {
    if(up[a][i] != up[b][i]) {
      a = up[a][i], b = up[b][i];
    }
  }

  return up[a][0];
}

int dist(int a, int b) {
  return depth[a] + depth[b] - 2 * depth[lca(a, b)];
}

int dfs_sz(int node, int parent) {
  sz[node] = 1, compSize++;
  for(auto i: adj[node]) {
    if(i == parent || used[i]) continue;
    sz[node] += dfs_sz(i, node);
  }
  return sz[node];
}

int get_centroid(int node, int parent) {
  for(auto i: adj[node]) {
    if(i == parent || used[i]) continue;
    if(2 * sz[i] > compSize) {
      return get_centroid(i, node);
    }
  }
  return node;
}

int find_centroid(int node, int parent) {
  compSize = 0;
  dfs_sz(node, 0);
  int centroid = get_centroid(node, 0);
  return centroid;
}

void centroid_decomposition() {
  queue<pair<int, int>> q;
  q.push({1, 0});
  dfs_lca(1, 0);

  while(!q.empty()) {
    auto u = q.front();
    q.pop();

    int centroid = find_centroid(u.first, 0);

    if(u.second) {
      p[centroid] = u.second;
    }

    used[centroid] = true;
    for(auto i: adj[centroid]) {
      if(used[i]) continue;
      q.push({i, centroid});
    }

  }
}

void init() {
  for(int i = 1; i <= n; i++) {
    best[i] = 1e8;
  }
}

void update(int node) {
  int curr = node;
  while(curr) {
    best[curr] = min(best[curr], dist(curr, node));
    curr = p[curr];
  }
}

int query(int node) {
  int curr = node, answ = best[curr];
  while(curr) {
    answ = min(answ, dist(curr, node) + best[curr]);
    curr = p[curr];
  }
  return answ;
}

void solve_() {
  cin >> n >> m;
  for(int i = 2; i <= n; i++) {
    int a; cin >> a, a++;
    adj[a].push_back(i);
    adj[i].push_back(a);
  }

  centroid_decomposition();
  
  //
  init();
  
  vector<pair<int, int>> order;

  for(int i = 1; i <= n; i++) {
    order.push_back({depth[i], i});
  }

  sort(rall(order));

  int answ = 0;
  for(int i = 1; i <= n; i++) {
    int distance = query(order[i - 1].second);
    if(distance < m) continue;
    update(order[i - 1].second);
    answ++;
  }

  printf("%d\n", answ);
}

int main() {
  setIO("");

  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };

  int test_cases = 1;
  solve(test_cases);

  return 0;
}

Compilation message

catinatree.cpp: In function 'void setIO(std::string)':
catinatree.cpp:63:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
catinatree.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 5016 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4980 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 2 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 5016 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4980 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 2 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct
21 Correct 5 ms 5332 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 3 ms 5076 KB Output is correct
25 Correct 4 ms 5204 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 3 ms 5200 KB Output is correct
28 Correct 4 ms 5204 KB Output is correct
29 Correct 4 ms 5204 KB Output is correct
30 Correct 5 ms 5204 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5204 KB Output is correct
33 Correct 3 ms 5204 KB Output is correct
34 Correct 4 ms 5204 KB Output is correct
35 Correct 3 ms 5204 KB Output is correct
36 Correct 3 ms 5204 KB Output is correct
37 Correct 3 ms 5204 KB Output is correct
38 Correct 4 ms 5204 KB Output is correct
39 Correct 4 ms 5204 KB Output is correct
40 Correct 4 ms 5400 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 5016 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 3 ms 4980 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 2 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct
21 Correct 5 ms 5332 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 3 ms 5076 KB Output is correct
25 Correct 4 ms 5204 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 3 ms 5200 KB Output is correct
28 Correct 4 ms 5204 KB Output is correct
29 Correct 4 ms 5204 KB Output is correct
30 Correct 5 ms 5204 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5204 KB Output is correct
33 Correct 3 ms 5204 KB Output is correct
34 Correct 4 ms 5204 KB Output is correct
35 Correct 3 ms 5204 KB Output is correct
36 Correct 3 ms 5204 KB Output is correct
37 Correct 3 ms 5204 KB Output is correct
38 Correct 4 ms 5204 KB Output is correct
39 Correct 4 ms 5204 KB Output is correct
40 Correct 4 ms 5400 KB Output is correct
41 Correct 147 ms 33196 KB Output is correct
42 Correct 210 ms 20352 KB Output is correct
43 Correct 171 ms 20360 KB Output is correct
44 Correct 188 ms 20300 KB Output is correct
45 Correct 169 ms 20244 KB Output is correct
46 Correct 500 ms 35648 KB Output is correct
47 Correct 448 ms 35652 KB Output is correct
48 Correct 463 ms 35668 KB Output is correct
49 Correct 484 ms 35644 KB Output is correct
50 Correct 115 ms 20676 KB Output is correct
51 Correct 110 ms 20692 KB Output is correct
52 Correct 124 ms 20680 KB Output is correct
53 Correct 248 ms 36292 KB Output is correct
54 Correct 281 ms 36204 KB Output is correct
55 Correct 279 ms 36204 KB Output is correct
56 Correct 6 ms 5420 KB Output is correct
57 Correct 31 ms 9908 KB Output is correct
58 Correct 171 ms 27304 KB Output is correct
59 Correct 498 ms 43588 KB Output is correct
60 Correct 136 ms 35168 KB Output is correct
61 Correct 281 ms 34072 KB Output is correct