#include "mushrooms.h"
#include<bits/stdc++.h>
using namespace std;
int K;
int askline(int l, int r) {
vector<int>toquest;
for (int i = l ; i <= r ; ++ i) toquest.emplace_back(i);
return use_machine(toquest);
}
int fnd(vector<int>unk, vector<int>giv) {
int ret = 0;
int cnt = (int)giv.size();
assert(cnt != 0);
int tfn = (int)unk.size();
for (int i = 0 ; i < tfn ; i += cnt) {
int l = i, r = min(tfn - 1, i + cnt - 1);
vector<int>crop;
for (int j = l ; j <= r ; ++ j) {
crop.emplace_back(unk[j]);
crop.emplace_back(giv[j-l]);
}
ret += (use_machine(crop) + 1) / 2;
}
return ret;
}
int count_mushrooms(int n) {
int cur = -1;
for (int k = 1 ; k <= n ; ++ k) {
int asked = n / k;
int ch = (asked + 1) / 2;
int others = n - asked;
int total = (others + ch - 1) / ch + asked;
if (cur == -1 || cur > total) {
cur = total;
K = k;
}
}
vector<int>who(n, 2); // 0 -> A, 1 -> B, 2 -> unknown
who[0] = 0;
for (int p = 0 ; p + K < n ; p += K) {
int ret = askline(p, p + K);
who[p + K] = who[p] ^ (ret & 1);
}
array<vector<int>, 3>vecs;
for (int i = 0 ; i < n ; ++ i) {
vecs[who[i]].emplace_back(i);
}
if (vecs[0].size() > vecs[1].size()) { // we will search the number of bs
return n - fnd(vecs[2], vecs[0]) - vecs[1].size();
} else { // the number of as
return fnd(vecs[2], vecs[1]) + vecs[0].size();
}
}
