#if !__INCLUDE_LEVEL__ #include __FILE__ /* (目的値)~正の無限 が条件を満たす場合 ng…条件を満たさない値の範囲での最大値 ok…条件を満たす値の範囲での最小値 ng < ok is_ok == Trueの場合、探索範囲が左半分へ is_ok == Falseの場合、探索範囲が右半分へ */ int main() { ll ok = 0; ll ng = 1000000001; while (abs(ng - ok) > 1) { ll mid = (ok + ng) / 2; int is_ok = 0; cout << "?" << " " << mid << endl; cin >> is_ok; if (is_ok) { ok = mid; } else { ng = mid; } } cout << "!" << " " << ok << endl; } #else #include #include using namespace std; using namespace atcoder; #define rep(i, n) for(int i = 0; i < n; i++) #define rrep(i, n) for(int i = n-1; i >= 0; i--) #define range(i, m, n) for(int i = m; i < n; i++) #define fore(i,a) for(auto &i:a) #define all(v) v.begin(), v.end() #define rall(v) v.rbegin(), v.rend() #define Sum(v) accumulate(all(v),ll(0)) #define minv(v) *min_element(all(v)) #define maxv(v) *max_element(all(v)) typedef long long ll; typedef vector vl; typedef vector> vvl; const ll INF = 1e16; const ll MOD1 = 1000000007; const ll MOD2 = 998244353; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } ll SN(char s){return ll(s-'0');} ll SN(string s){return stoll(s);} int alpN(char s){return int(s-'a');} int AlpN(char s){return int(s-'A');} using Graph = vector>; using GraphCost = vector>>; using mint1 = modint1000000007; using mint2 = modint998244353; using pll = pair; template ostream &operator<<(ostream &o,const vector&v){for(int i=0;i<(int)v.size();i++)o<<(i>0?" ":"")< bool contain(const std::string& s, const T& v) { return s.find(v) != std::string::npos; } ll max(int x,ll y){return max((ll)x,y);} ll max(ll x,int y){return max(x,(ll)y);} ll min(int x,ll y){return min((ll)x,y);} ll min(ll x,int y){return min(x,(ll)y);} #endif