Submission #626747

#	Time	Username	Problem	Language	Result	Execution time	Memory
626747		flashmt	Prisoner Challenge (IOI22_prison)	C++17	90 / 100	13 ms	1108 KiB

prison

#include <bits/stdc++.h>
using namespace std;
// 3 ** 6 * 7 > 5000
const int BASE = 3;
const int POWER = 6;
const int REMAIN = 7;

vector<vector<int>> devise_strategy(int n) {
  vector<vector<int>> ans;
  vector<vector<int>> digits(729);
  for (int i = 0; i < 729; i++)
  {
    for (int j = 0, x = i; j < POWER; j++)
    {
      digits[i].push_back(x % BASE);
      x /= BASE;
    }
    reverse(begin(digits[i]), end(digits[i]));
  }

  // 0
  {
    vector<int> a = {0};
    for (int j = 0; j < n; j++)
      a.push_back(digits[j / REMAIN][0] + 1);
    ans.push_back(a);
  }

  // [1, 18]
  for (int i = 0; i < POWER; i++)
    for (int x = 0; x < BASE; x++)
    {
      int otherBag = i % 2, curBag = otherBag ^ 1;
      vector<int> a = {curBag};
      for (int j = 0; j < n; j++)
      {
        auto curDigits = digits[j / REMAIN];
        if (curDigits[i] < x) a.push_back(-curBag - 1);
        else if (curDigits[i] > x) a.push_back(-otherBag - 1);
        else if (i < POWER - 1) a.push_back((i + 1) * BASE + curDigits[i + 1] + 1);
        else // last digit
        {
          int rem = j % REMAIN;
          if (rem == 0) a.push_back(-curBag - 1);
          else if (rem == 6) a.push_back(-otherBag - 1);
          else if (rem <= 2) a.push_back(19); // 1, 2
          else if (rem <= 4) a.push_back(20); // 3, 4
          else a.push_back(21); // 5
        }
      }

      ans.push_back(a);
    }

  // [19, 21]
  for (int i : {19, 20, 21})
  {
    int otherBag = 0, curBag = 1;
    vector<int> a = {1};
    for (int j = 0; j < n; j++)
    {
      int rem = j % REMAIN;
      if (rem <= 1) a.push_back(-curBag - 1);
      else if (rem >= 5) a.push_back(-otherBag - 1);
      else if (rem <= 3) a.push_back(-(i == 19 ? otherBag : curBag) - 1);
      else a.push_back(-(i == 21 ? curBag : otherBag) - 1);
    }

    ans.push_back(a);
  }

  return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 80 / 90