Submission #413147

#	Time	Username	Problem	Language	Result	Execution time	Memory
413147		schse	Combo (IOI18_combo)	C++14	100 / 100	55 ms	448 KiB

combo

#include "combo.h"
#ifndef EVAL
#include "grader.cpp"
#endif
#include <string>
#include <vector>

using namespace std;

std::string guess_sequence(int N)
{
  string known = "";
  if (press("AB"))
    known = (press("A") ? "A" : "B");
  else
    known = (press("X") ? "X" : "Y");
  vector<char> letters;
  if (known != "A")
    letters.push_back('A');
  if (known != "B")
    letters.push_back('B');
  if (known != "X")
    letters.push_back('X');
  if (known != "Y")
    letters.push_back('Y');
  if (N == 1)
    return known;
  for (int i = 1; i < N - 1; i++)
  {
    string str;
    str = known;
    str.push_back(letters[1]);

    str.append(known);
    str.push_back(letters[2]);
    str.push_back(letters[0]);

    str.append(known);
    str.push_back(letters[2]);
    str.push_back(letters[1]);

    str.append(known);
    str.push_back(letters[2]);
    str.push_back(letters[2]);

    known.push_back(letters[press(str) - known.size()]);
  }

  string str1, str2, str3;
  str1.push_back(letters[0]);
  str2.push_back(letters[1]);
  str3.push_back(letters[2]);

  if (press(known + str1) == N)
    return known + str1;
  if (press(known + str2) == N)
    return known + str2;
  return known + str3;
}

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95