Submission #1204248

#	Time	Username	Problem	Language	Result	Execution time	Memory
1204248		12baater	Combo (IOI18_combo)	C++20	100 / 100	7 ms	468 KiB

combo

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

using namespace std;

string guess_sequence(int N) {
  string buttons[4] = {"A","B","X","Y"};
  vector<string> notFirst;
  string k = "";
  int kLength = 1;
  string first = "A";
  int coins = press("AB");
  if (coins >= 1) {
    coins = press("A");
    if (coins == 1) first = "A";
    else first = "B";
  } else {
    coins = press("Y");
    if (coins == 1) first = "Y";
    else first = "X";
  }
  k += first;
  for(int i = 0; i < 4; i++) {
    if (buttons[i] == first) continue;
    notFirst.push_back(buttons[i]);
  }

  while(kLength+2 <= N) {
    coins = press(k+notFirst[0]+k+notFirst[1]+notFirst[0]+k+notFirst[1]+notFirst[1]+k+notFirst[1]+notFirst[2]);
    if(coins == kLength) {
      k += notFirst[2];
      kLength++;
    } else if (coins == kLength+1) {
      k += notFirst[0];
      kLength++;
    } else {
      k += notFirst[1];
      kLength++;
    }
  }
  if (N>1) {
    coins = press(k+notFirst[0]+k+notFirst[1]);
    if (coins == kLength+1) {
      coins = press(k+notFirst[0]);
      if (coins == kLength+1) {
        k += notFirst[0];
      } else {
        k += notFirst[1];
      }
    } else {
      k += notFirst[2];
    }
  }
  return k;
}

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