#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
using str = string;
#define rep(x) for (auto &x : CHARS)
#define each(x, a) for (auto &x : a)
default_random_engine rng;
str guess_sequence(int N) {
rng = default_random_engine(chrono::system_clock::now().time_since_epoch().count());
vector<str> CHARS = {"A", "B", "X", "Y"};
shuffle(CHARS.begin(), CHARS.end(), rng);
str fst = CHARS[0];
if (N == 1) {
for (int i = 1; i <= 3; i++) {
if (press(CHARS[i]) == 1) {
fst = CHARS[i];
break;
}
}
} else {
if (press("AB") == 1) {
fst = press("A") == 1 ? "A" : "B";
} else {
fst = press("X") == 1 ? "X" : "Y";
}
}
vector<string> nchars; for (int i = 0; i < 4; i++) if (CHARS[i] != fst) nchars.push_back(CHARS[i]);
str pref = fst;
while (pref.size() < N) {
int curn = pref.size();
bool found = false;
shuffle(nchars.begin(), nchars.end(), rng);
if (curn >= N-1) {
if (press(pref + nchars[0]) > curn) {
found = true;
pref += nchars[0];
} else if (press(pref + nchars[1]) > curn) {
found = true;
pref += nchars[1];
}
} else {
string gs = pref + nchars[0] + fst +
pref + nchars[1] + nchars[0] +
pref + nchars[1] + nchars[1] +
pref + nchars[1] + nchars[2];
int ans = press(gs);
if (ans == curn+1) {
pref += nchars[0];
found = true;
} else if (ans == curn+2) {
pref += nchars[1];
found = true;
}
}
if (found == false) pref += nchars[2];
}
return pref;
}
