oj.uz

답안 #784615

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
784615 2023-07-16T11:05:37 Z cadmiumsky Mousetrap (CEOI17_mousetrap) C++17
20 / 100
 232 ms 62824 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 = 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

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23740 KB Output is correct
3 Correct 11 ms 23768 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 11 ms 23788 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 16 ms 23764 KB Output is correct
8 Correct 12 ms 23772 KB Output is correct
9 Correct 12 ms 23744 KB Output is correct
10 Correct 11 ms 23744 KB Output is correct

Subtask #2
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 232 ms 62824 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23740 KB Output is correct
3 Correct 11 ms 23768 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 11 ms 23788 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 16 ms 23764 KB Output is correct
8 Correct 12 ms 23772 KB Output is correct
9 Correct 12 ms 23744 KB Output is correct
10 Correct 11 ms 23744 KB Output is correct
11 Correct 12 ms 23764 KB Output is correct
12 Correct 14 ms 23764 KB Output is correct
13 Correct 12 ms 23808 KB Output is correct
14 Correct 12 ms 23892 KB Output is correct
15 Correct 12 ms 23896 KB Output is correct
16 Correct 12 ms 23840 KB Output is correct
17 Incorrect 12 ms 23752 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 23764 KB Output is correct
2 Correct 12 ms 23740 KB Output is correct
3 Correct 11 ms 23768 KB Output is correct
4 Correct 12 ms 23764 KB Output is correct
5 Correct 11 ms 23788 KB Output is correct
6 Correct 11 ms 23764 KB Output is correct
7 Correct 16 ms 23764 KB Output is correct
8 Correct 12 ms 23772 KB Output is correct
9 Correct 12 ms 23744 KB Output is correct
10 Correct 11 ms 23744 KB Output is correct
11 Incorrect 232 ms 62824 KB Output isn't correct
12 Halted 0 ms 0 KB -