oj.uz

답안 #784614

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
784614 2023-07-16T11:05:13 Z cadmiumsky Mousetrap (CEOI17_mousetrap) C++17
20 / 100
 239 ms 74448 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] = 1;
  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++) {
    for(auto x : adj[i])
      if(x > threshold) threshold--, tolerance--;
      else break;
    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;
    //cerr << M << '\n';
    M = p[M];
    sort(all(adj.back()), greater<int>());
    
    //for(auto x : adj.back())
      //cerr << x << ' ';
    //cerr << '\n';
  }
  
  int sum = -1;
  for(int i = 0; i < sz(adj); i++) {
    sum += sz(rbegin(adj)[i]);
    for(auto &x : rbegin(adj)[i]) x += sum;
  }
  
  //for(auto v : adj) {
    //for(auto x : v)
      //cerr << x << ' ';
    //cerr << '\n';
  //}
  
  //cerr << " > " << crapa(3) << '\n';
  
  int lim = -1;
  for(int step = 18; 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

# 결과 실행 시간 메모리 Grader output
1 Correct 11 ms 23724 KB Output is correct
2 Correct 12 ms 23808 KB Output is correct
3 Correct 12 ms 23684 KB Output is correct
4 Correct 14 ms 23800 KB Output is correct
5 Correct 14 ms 23796 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23784 KB Output is correct
8 Correct 11 ms 23756 KB Output is correct
9 Correct 10 ms 23764 KB Output is correct
10 Correct 13 ms 23764 KB Output is correct

Subtask #2
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 239 ms 74448 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 11 ms 23724 KB Output is correct
2 Correct 12 ms 23808 KB Output is correct
3 Correct 12 ms 23684 KB Output is correct
4 Correct 14 ms 23800 KB Output is correct
5 Correct 14 ms 23796 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23784 KB Output is correct
8 Correct 11 ms 23756 KB Output is correct
9 Correct 10 ms 23764 KB Output is correct
10 Correct 13 ms 23764 KB Output is correct
11 Correct 16 ms 23756 KB Output is correct
12 Correct 12 ms 23764 KB Output is correct
13 Correct 12 ms 23848 KB Output is correct
14 Correct 12 ms 23892 KB Output is correct
15 Correct 12 ms 23812 KB Output is correct
16 Correct 12 ms 23784 KB Output is correct
17 Incorrect 12 ms 23764 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 11 ms 23724 KB Output is correct
2 Correct 12 ms 23808 KB Output is correct
3 Correct 12 ms 23684 KB Output is correct
4 Correct 14 ms 23800 KB Output is correct
5 Correct 14 ms 23796 KB Output is correct
6 Correct 12 ms 23764 KB Output is correct
7 Correct 12 ms 23784 KB Output is correct
8 Correct 11 ms 23756 KB Output is correct
9 Correct 10 ms 23764 KB Output is correct
10 Correct 13 ms 23764 KB Output is correct
11 Incorrect 239 ms 74448 KB Output isn't correct
12 Halted 0 ms 0 KB -