Submission #573113

#	Time	Username	Problem	Language	Result	Execution time	Memory
573113		dnialh	Combo (IOI18_combo)	C++17	100 / 100	29 ms	604 KiB

combo

#include "combo.h"
#include <vector>

using namespace std;

string guess_sequence(int N) {
  string p = "AB";
  int coins = press(p);

  string start;

  if (coins){
    string q = "A";
    coins = press(q);

    if (coins){
      start = "A";
    } else {
      start = "B";
    }
  } else {
    string q = "X";
    coins = press(q);

    if (coins){
      start = "X";
    } else {
      start = "Y";
    }
  }

  if (N == 1) return start;

  vector<string> other;

  if (start != "A"){
    other.push_back("A");
  }
  if (start != "B"){
    other.push_back("B");
  }
  if (start != "X"){
    other.push_back("X");
  }
  if (start != "Y"){
    other.push_back("Y");
  }

  string S = start;
  for (int i = 1; i < N - 1; ++i) {
    string query = S + other[1];
    query += (S + other[2] + other[0]);
    query += (S + other[2] + other[1]);
    query += (S + other[2] + other[2]);

    int res = press(query);

    S += other[res - i];
  }


  int r1 = press(S + other[0]);
  if (r1 == N){
    return S + other[0];
  }
  
  int r2 = press(S + other[1]);
  if (r2 == N){
    return S + other[1];
  }

  return S + other[2];
}

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