#include <bits/stdc++.h>
#include "cave.h"
using namespace std;
#define SZ(v) ((int)(v).size())
//void answer(int S[], int D[]);
//int tryCombination(int S[]);
void exploreCave(int nb_portes)
{
int switches[nb_portes], portes[nb_portes];
for (int i(0); i < nb_portes; ++i)
switches[i] = 0;
vector<bool> fixed(nb_portes);
int lst_ans(tryCombination(switches));
if (lst_ans == -1)
lst_ans = nb_portes;
auto flip_range = [&](int left, int right)
{
for (int i(left); i <= right; ++i)
if (!fixed[i])
switches[i] ^= 1;
};
for (int i(0); i < nb_portes; ++i)
{
int lft(0), rgt(nb_portes-1);
while (lft < rgt)
{
int mid = (lft + rgt)/2;
flip_range(lft, mid);
int nxt_ans = tryCombination(switches);
if (nxt_ans == -1)
nxt_ans = nb_portes;
flip_range(lft, mid);
if ((lst_ans <= i and nxt_ans > i) or (lst_ans > i and nxt_ans <= i))
rgt = mid;
else
lft = mid+1;
}
assert(!fixed[lft]);
if (lst_ans <= i)
{
switches[lft] ^= 1;
lst_ans = tryCombination(switches);
if (lst_ans == -1)
lst_ans = nb_portes;
}
fixed[lft] = true;
portes[lft] = i;
assert(lst_ans > i);
}
answer(switches, portes);
}
