Submission #629323

#	Time	Username	Problem	Language	Result	Execution time	Memory
629323		jakubd	Rarest Insects (IOI22_insects)	C++17	100 / 100	252 ms	45296 KiB

insects

#include "insects.h"

#include <bits/stdc++.h>

using namespace std;

int N;
vector<int> where, lastWhere;

void _move_inside(int x) {
  where[x] = 1;
}

void _move_outside(int x) {
  where[x] = 0;
}

map<vector<int>, int> memo;
int _press_button() {
  if (memo.count(where)) return memo[where];
  for (int i = 0; i < N; i++) {
    if (where[i] == lastWhere[i]) continue;
    if (where[i]) move_inside(i);
    else move_outside(i);
  }
  lastWhere = where;
  return memo[where] = press_button();
}

int min_cardinality(int n) {
  N = n;
  int D = 0;
  where.resize(N), lastWhere.resize(N);
  vector<int> can, in, out;

  for (int i = 0; i < N; i++) {
    _move_inside(i);
    if (_press_button() == 2) {
      _move_outside(i);
      out.push_back(i);
    } else {
      D++;
      in.push_back(i);
    }
  }
  can = out;

  int l = 2, r = N / D, ans = 1, cnt = D;
  while (l <= r) {
    int m = (l + r + 1) / 2;

    in.resize(0), out.resize(0);
    for (int i : can) {
      if (cnt == D * m) {
        out.push_back(i);
        continue;
      }

      _move_inside(i);
      if (_press_button() > m) {
        _move_outside(i);
        out.push_back(i);
      } else {
        in.push_back(i);
        cnt++;
      }
    }

    if (cnt == D * m) {
      l = m + 1;
      ans = m;
      can = out;
    } else {
      r = m - 1;
      can = in;
      for (auto x : can) {
        _move_outside(x);
        cnt--;
      }
    }
  }

  return ans;
}

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