Submission #1124320

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124320		epicci23	Rarest Insects (IOI22_insects)	C++17	0 / 100	0 ms	416 KiB

insects

#include "insects.h"
#include "bits/stdc++.h"
using namespace std;

const int N = 2e3 + 5;

int vis[N], D , tot = 0 , Kill[N];
vector<int> Insects;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

inline bool Add(int x){
  if(vis[x] || Kill[x]) return 0;
  vis[x]=1;
  tot++;
  move_inside(x);
  return 1;
}

inline bool Rem(int x){
  if(!vis[x] || Kill[x]) return 0;
  vis[x]=0;
  tot--;
  move_outside(x);
  return 1;
}

inline int Get(){
  return press_button();
}

int min_cardinality(int n){
  for(int i=0;i<n;i++) Insects.push_back(i);
  shuffle(Insects.begin(),Insects.end(),rng);
  for(int i:Insects){
    Add(i);
    if(i == 0 || Get() == 1) continue;
    Rem(i);
  }
  for(int i=0;i<n;i++) if(vis[i]) Kill[i] = 1;
  D = tot;
  if(D > n / 2) return 1;
  if(D == 1) return n;

  int ans = 1, l = 2 , r = n / D;
  while(l <= r){
    int B = (l + r) / 2;
    for(int i:Insects) if(!Kill[i]) Rem(i);
    vector<int> to_kill;
    for(int i:Insects){
      if(vis[i] || Kill[i]) continue;
      Add(i);
      if(tot > B && Get() > B){
       Rem(i); 
       to_kill.push_back(i);
      }
    }
    if(tot == B * D){
      l = B + 1;
      ans = B;
      r = min(r, B + (int) to_kill.size() / D);
      if(to_kill.size() < D) return ans;
      for(int i=0;i<n;i++) if(vis[i]) Kill[i] = 1;
    }
    else{
      for(int x : to_kill) Kill[x] = 1;
      r = min(tot / D, B - 1);
    }
  }

  return ans;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 75