//#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using arr = array<int, 2>;
using arrr = array<int, 3>;
set <ll> used;
int query(ll p)
{
used.insert(p);
cout << "? " << p << endl;
int a;
cin >> a;
return a;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll n;
cin >> n;
if (n == 3) {
int a, b;
query(1);
a = query(3);
b = query(2);
if (a == 0) cout << "= " << 3 << "\n";
else if (b == 0) cout << "= " << 2 << "\n";
else cout << "= " << 1 << "\n";
return 0;
}
vector <ll> seq = { n };
for (ll i = 0; seq.size() == 1 || abs(seq[i - 1] - seq[i]) >= n / 2; i++)
{
seq.emplace_back(seq.back() + (n - (1ll << i)) * (i & 1 ? 1 : -1));
}
if (seq[seq.size() - 1] == seq[seq.size() - 2]) seq.pop_back();
// for (ll i : seq) cout << i << " ";
// cout << "\n";
ll dd = 62 - __builtin_clzll(n);
ll a, b, d;
a = seq.back(), b = seq[seq.size() - 2];
d = abs(a - b);
bool add = (a < b);
ll l = 1, r = n;
query(a);
int ans;
while (l != r)
{
a += (add ? d : -d);
ans = query(a);
if (ans)
{
r = d;
d -= (1ll << dd);
while (d < 1 && l != r)
{
d += (1ll << dd);
dd--;
d -= (1ll << dd);
}
} else {
l = d + 1;
d += (1ll << dd);
while (d >= n && l != r)
{
d -= (1ll << dd);
dd--;
d += (1ll << dd);
}
}
dd--;
add ^= 1;
}
// cerr << l << " " << r << "\n";
cout << "= " << l << "\n";
// cerr << used.size() << "\n";
}
// 1000000000000000000
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |