#include "combo.h" #include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int i=j;i<k;i++) const char L[] = "ABXY"; int twoN (const string& s) { int c = press(s+L[0]+s+L[1]); int k = 2 * (c <= s.length()); c = press(s+L[k]); k += (c <= s.length()); return k; } string guess_sequence(int N) { string s; int a[4]; FOR(i,0,4) { a[i] = i; } int k = twoN(s); s += L[k]; swap(a[k], a[3]); FOR(i,0,N-2) { string z; FOR(j,0,3) { z += s + L[a[0]] + L[a[j]]; } z += s + L[a[1]]; int cyc = press(z); if (cyc == i+2) { s += L[a[1]]; } else if (cyc == i+3) { s += L[a[0]]; } else { s += L[a[2]]; } } if (N>1) { int k = twoN(s); s += L[k]; } return s; } /* 2N bound FOR(i,0,N) { int c = press(s+L[0]+s+L[1]); int k = 2 * (c <= i); c = press(s+L[k]); k += (c <= i); s += L[k]; } */