#include "combo.h"
#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
string guess_sequence(int N) {
string p;
for (char c : {'A', 'B', 'X'}) {
p.pb(c);
if (press(p)) {
for (int i = 1; i < N; i++) {
p.pb(c);
}
break;
}
p.pop_back();
}
if (p.empty()) {
p.pb('Y');
for (int i = 1; i < N; i++) {
p.pb('Y');
}
}
vector<char> v;
for (char i : {'A', 'B', 'X', 'Y'}) {
if (p[0] == i) continue;
v.pb(i);
}
int idx = 1;
while (idx < N) {
for (int j = 0; j < 3; j++) {
int k = j + rand() % (3 - j);
swap(v[j], v[k]);
}
for (int i = idx+1; i - idx + 1 <= idx && i < N; i++) {
p[i] = v[rand() % 3];
}
int temp = idx;
for (int i = 0; i < 2; i++) {
if (p[idx] == v[i]) continue;
p[idx] = v[i];
int x = press(p);
if (x > idx) {
idx = x;
break;
}
}
if (idx == temp) {
p[idx] = v[2];
idx = press(p);
}
}
return p;
}
