#include "combo.h"
#include <iostream>
using namespace std;
const string letters = "ABXY";
std::string guess_sequence(int N) {
// cerr << "N:" << N << endl;
string res;
// determine first letter
char matched_first_char;
string cand = letters.substr(0, 2);
int coins = press(cand);
if (coins == 2) {
res += cand;
matched_first_char = cand[0];
}
else {
if (coins == 0)
cand = letters.substr(2);
coins = press(cand.substr(0, 1));
matched_first_char = cand[ coins == 0 ? 1 : 0 ];
res += matched_first_char;
}
cand = letters;
int p = cand.find(matched_first_char);
swap(cand[p], cand[3]);
// cerr << "cand: " << cand << endl;
// determine letters upto N-1
for (int n = res.size(); n < N-1; ++n) {
string guess = res;
guess += cand[1];
for (int k = 0; k < 3; ++k) {
guess += res;
guess += cand[2];
guess += cand[k];
}
coins = press(guess);
int k = coins - res.size();
// cerr << "n:" << n << " guess:" << guess << " coins:" << coins << endl;
res += cand[k];
// cerr << "res:" << res << endl;
}
// determine last letter
{
string guess = res;
guess += cand[0];
guess += cand[3];
guess += res;
guess += cand[1];
coins = press(guess);
if (coins == N) {
guess = res + cand[0];
coins = press(guess);
if (coins == N)
res += cand[0];
else
res += cand[1];
}
else
res += cand[2];
}
// cerr << "res: " << res << endl;
return res;
}
