Submission #1259835

#	Time	Username	Problem	Language	Result	Execution time	Memory
1259835		sokratisi	Combo (IOI18_combo)	C++20	5 / 100	0 ms	396 KiB

combo

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

using namespace std;

int coins;
string use;

//int press(string p);

char find_first() {
  use = "AB";
  coins = press(use);
  if (coins) {
    use = "A";
    coins = press(use);
    if (coins) return 'A';
    else return 'B';  
  }
  use = "X";
  coins = press(use);
  if (coins) return 'X';
  else return 'Y';
}

string guess_sequence(int n) {
  char c = find_first();
  set<char> s = {'A', 'B', 'X', 'Y'};
  s.erase(c);
  vector<char> chrs;
  for (auto u: s) chrs.push_back(u);

  string p = "";
  p += c;
  for (int i = 2; i <= n - 1; i++) {
    use = p + chrs[0] + chrs[0] + p + chrs[0] + chrs[1] + p + chrs[0] + chrs[2] + p + chrs[1];
    int coins = press(use);
    if (coins == i + 1) p += chrs[0];
    else if (coins == i) p += chrs[1];
    else p += chrs[2];
  }
  use = p + chrs[0];
  coins = press(use);
  if (coins == n) return use;
  use = p + chrs[1];
  coins = press(use);
  if (coins == n) return use;
  return (p + chrs[2]);
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95