oj.uz

Submission #784640

# Submission time Handle Problem Language Result Execution time Memory
784640 2023-07-16T11:24:40 Z cadmiumsky Mousetrap (CEOI17_mousetrap) C++17
100 / 100
 905 ms 185932 KB 
#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;
using ld = long double;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 1e6 + 5;

int dp[nmax], p[nmax];
vector<int> g[nmax];

vector<vector<int>> adj;

void initp(int node, int f) {
  p[node] = f;
  for(auto x : g[node]) if(x != f) initp(x, node);
}

void initdp(int node, int f) {
  //cerr << node << '\n';
  vector<int> vs;
  for(auto x : g[node]) {
    if(x == f) continue;
    initdp(x, node);
    vs.emplace_back(dp[x]);
  }
  sort(all(vs));
  if(sz(vs) < 2) dp[node] = sz(vs);
  else dp[node] = sz(vs) + rbegin(vs)[1];
  return;
}

bool crapa(int threshold) {
  int tolerance = 1;
  for(int i = 0; i < sz(adj); tolerance++, i++) {
    int cnt = 0;
    for(auto x : adj[i])
      if(x > threshold) cnt++, tolerance--;
      else break;
    threshold -= cnt;
    if(tolerance < 0 || threshold < 0) return 1;
  }
  return 0;
  
}

signed main() {
  cin.tie(0) -> sync_with_stdio(0);
  int n, T, M;
  cin >> n >> T >> M;
  for(int i = 1, x, y; i < n; i++) {
    cin >> x >> y;
    g[x].emplace_back(y);
    g[y].emplace_back(x);
  }
  
  initp(T, T);
  int prv = -1;
  while(M != T) {
    adj.emplace_back();
    for(auto x : g[M]) {
      if(x == p[M] || x == prv) continue;
      initdp(x, M);
      adj.back().emplace_back(dp[x]);
    }
    prv = M;
    M = p[M];
    sort(all(adj.back()), greater<int>());
  }
  
  //for(auto x : adj) {
    //for(auto y : x) cerr << y << ' ';
    //cerr << '\n';
  //}
  int sum = 0;
  for(int i = 0; i < sz(adj); i++) {
    sum += sz(rbegin(adj)[i]);
    for(auto &x : rbegin(adj)[i]) x += sum;
  }
  
  //for(auto x : adj) {
    //for(auto y : x) cerr << y << ' ';
    //cerr << '\n';
  //}
  
  int lim = -1;
  for(int step = 21; step >= 0; step--)
    if(crapa(lim + (1 << step))) lim += (1 << step);
  
  cout << lim + 1 << '\n';;
  
}

/**
      Anul asta se da centroid.
-- Surse oficiale
*/

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 11 ms 23764 KB Output is correct
4 Correct 11 ms 23816 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 11 ms 23768 KB Output is correct
8 Correct 11 ms 23764 KB Output is correct
9 Correct 11 ms 23776 KB Output is correct
10 Correct 12 ms 23820 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 256 ms 76276 KB Output is correct
2 Correct 228 ms 70904 KB Output is correct
3 Correct 815 ms 77204 KB Output is correct
4 Correct 358 ms 50332 KB Output is correct
5 Correct 763 ms 77168 KB Output is correct
6 Correct 877 ms 77236 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 11 ms 23764 KB Output is correct
4 Correct 11 ms 23816 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 11 ms 23768 KB Output is correct
8 Correct 11 ms 23764 KB Output is correct
9 Correct 11 ms 23776 KB Output is correct
10 Correct 12 ms 23820 KB Output is correct
11 Correct 10 ms 23764 KB Output is correct
12 Correct 11 ms 23820 KB Output is correct
13 Correct 12 ms 23764 KB Output is correct
14 Correct 11 ms 23916 KB Output is correct
15 Correct 12 ms 23800 KB Output is correct
16 Correct 12 ms 23764 KB Output is correct
17 Correct 11 ms 23764 KB Output is correct
18 Correct 11 ms 23872 KB Output is correct
19 Correct 10 ms 23764 KB Output is correct
20 Correct 10 ms 23764 KB Output is correct
21 Correct 10 ms 23828 KB Output is correct
22 Correct 10 ms 23816 KB Output is correct

Subtask #4
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 11 ms 23764 KB Output is correct
3 Correct 11 ms 23764 KB Output is correct
4 Correct 11 ms 23816 KB Output is correct
5 Correct 11 ms 23764 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 11 ms 23768 KB Output is correct
8 Correct 11 ms 23764 KB Output is correct
9 Correct 11 ms 23776 KB Output is correct
10 Correct 12 ms 23820 KB Output is correct
11 Correct 256 ms 76276 KB Output is correct
12 Correct 228 ms 70904 KB Output is correct
13 Correct 815 ms 77204 KB Output is correct
14 Correct 358 ms 50332 KB Output is correct
15 Correct 763 ms 77168 KB Output is correct
16 Correct 877 ms 77236 KB Output is correct
17 Correct 10 ms 23764 KB Output is correct
18 Correct 11 ms 23820 KB Output is correct
19 Correct 12 ms 23764 KB Output is correct
20 Correct 11 ms 23916 KB Output is correct
21 Correct 12 ms 23800 KB Output is correct
22 Correct 12 ms 23764 KB Output is correct
23 Correct 11 ms 23764 KB Output is correct
24 Correct 11 ms 23872 KB Output is correct
25 Correct 10 ms 23764 KB Output is correct
26 Correct 10 ms 23764 KB Output is correct
27 Correct 10 ms 23828 KB Output is correct
28 Correct 10 ms 23816 KB Output is correct
29 Correct 12 ms 23812 KB Output is correct
30 Correct 247 ms 76236 KB Output is correct
31 Correct 241 ms 76216 KB Output is correct
32 Correct 292 ms 119792 KB Output is correct
33 Correct 291 ms 185932 KB Output is correct
34 Correct 850 ms 77176 KB Output is correct
35 Correct 889 ms 77208 KB Output is correct
36 Correct 905 ms 84300 KB Output is correct
37 Correct 897 ms 84232 KB Output is correct
38 Correct 578 ms 86224 KB Output is correct
39 Correct 615 ms 86200 KB Output is correct
40 Correct 612 ms 86176 KB Output is correct