#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 450;
vector<array<int, 3> > results;
int N;
bool cmp(array<int, 3> a, array<int, 3> b)
{
return ((a[0] + a[1]) > (b[0] + b[1]));
}
int DivideAndConquer(int l, int r)
{
// cout << "l = " << l << ", r = " << r << "\n";
if(l > r)
{
return -1;
}
if(l == 0 && r == N - 1)
{
int value1 = -1, value2 = -1;
if(results[0][0] != 0)
{
value1 = DivideAndConquer(l, results[0][2] - 1);
}
if(results[0][1] != 0)
{
value2 = DivideAndConquer(results[0][2] + 1, r);
}
// cout << "value1 = " << value1 << ", value2 = " << value2 << "\n";
if(results[0][0] == 0 && results[0][1] == 0)
{
return results[0][2];
}
if(value1 == -1)
{
return value2;
}
return value1;
}
int mid = (l + r) >> 1;
vector<int> reply = ask(mid);
if(reply[0] + reply[1] == 0)
{
// cout << "mid = " << mid << "\n";
return mid;
}
int value1 = -1, value2 = -1;
if(reply[0] != 0)
{
value1 = DivideAndConquer(l, mid - 1);
}
if(reply[1] != 0)
{
value2 = DivideAndConquer(mid + 1, r);
}
if(value1 == -1 && value2 == -1)
{
return -1;
}
if(value1 == -1)
{
return value2;
}
return value1;
}
int find_best(int n)
{
N = n;
int mid = n / 2;
// results.push_back({2, 1, 4});
for(int i = max(0, mid - MAXN / 2); i < min(n, mid + MAXN / 2 + 1); i++)
{
vector<int> reply = ask(i);
if(reply[0] + reply[1] == 0)
{
return i;
}
results.push_back({reply[0], reply[1], i});
}
sort(results.begin(), results.end(), cmp);
return DivideAndConquer(0, n - 1);
}
