#include "mushrooms.h"
#include<bits/stdc++.h>
using namespace std;
#define forinc(i,a,b) for(int i=a;i<=b;i++)
#define fordec(i,a,b) for(int i=a;i>=b;i--)
#define fi first
#define se second
#define pb push_back
//#define int long long
#define ll __int128
#define mp make_pair
#define nn "\n"
#define fasty ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
int in,res,debug,cnt,len,k,n;
int a[1000000];
/*
int use_machine(vector<int> x){
cnt++; len+=x.size(); if(len>100000) cout << "wa2 " << len << nn;
int ans=0;
//forinc(i,0,x.size()-1) forinc(j,i+1,x.size()-1) if(x[i]==x[j]) cout << "wa1" << nn;
forinc(i,1,x.size()-1){
if(a[x[i]]!=a[x[i-1]]) ans++;
}
return ans;
}
*/
int count_mushrooms(int n){
/*
cost=k+2*i
n=2*(k+k+k+1+...+(k+i-1));
~ (2*k+i)*i
3*n <= (2*k+i)*(3*i) <= (k+2*i)^2 => k=sqrt(n/3)
*/
bool stt; int cut=(int)(sqrt(n/3));
vector<int> A, B; A.pb(0);
int pt=1;
// step 1;
for(;pt<n;pt++){
vector<int> out{0,pt}; debug=2; res=use_machine(out);
if(res) B.pb(pt);
else A.pb(pt);
if(A.size()==2){
stt=1; pt++; break;
}
if(B.size()==2){
stt=0; pt++; break;
}
}
//cout << pt << " " << 1 << nn;
// step 2
if(n>10){
if(stt){
for(;pt<n;pt+=2){
vector<int> out{A[0],pt,A[1],pt+1}; debug=4; res=use_machine(out);
if(res==0){
A.pb(pt); A.pb(pt+1);
} else if(res==1){
A.pb(pt); B.pb(pt+1);
} else if(res==2){
B.pb(pt); A.pb(pt+1);
} else{
B.pb(pt); B.pb(pt+1);
} if(A.size()>=cut){
stt=1; pt+=2; break;
} if(B.size()>=cut){
stt=0; pt+=2; break;
}
}
}
else{
for(;pt<n;pt+=2){
vector<int> out{B[0],pt,B[1],pt+1}; debug=4; res=use_machine(out);
if(res==0){
B.pb(pt); B.pb(pt+1);
} else if(res==1){
B.pb(pt); A.pb(pt+1);
} else if(res==2){
A.pb(pt); B.pb(pt+1);
} else{
A.pb(pt); A.pb(pt+1);
} if(A.size()>=cut){
pt+=2; break;
} if(B.size()>=cut){
pt+=2; break;
}
}
}
}
//cout << pt << " " << 2 << nn;
// step 3
int ans=A.size();
while(pt<n){
if(A.size()>B.size()){
k=A.size();
vector<int> out; debug=2*min(k,n-pt); forinc(i,0,debug/2-1){
out.pb(A[i]);
out.pb(pt);
pt++;
}
res=use_machine(out);
ans+=debug/2-(res+1)/2;
if(res%2) B.pb(pt-1);
else A.pb(pt-1);
}
else{
k=B.size();
vector<int> out; debug=2*min(k,n-pt); forinc(i,0,debug/2-1){
out.pb(B[i]);
out.pb(pt);
pt++;
}
res=use_machine(out);
ans+=(res+1)/2;
if(res%2) A.pb(pt-1);
else B.pb(pt-1);
}
}
//cout << pt << " " << 3 << nn;
return ans;
}
/*
signed main(){
std::random_device rd; // a seed source for the random number engine
std::mt19937 gen(rd()); // mersenne_twister_engine seeded with rd()
std::uniform_int_distribution<> distrib(0,1);
std::uniform_int_distribution<> d(18000,20000);
bool Stt=true; int ANS=0;
int t; cin >> t; while(t--){
cnt=len=in=0;
if(t==0){
n=20000;
forinc(i,0,n-1) {
a[i]=i%2; if(a[i]==0) in++;
}
}
else{
n=d(gen);
a[0]=0; in=1;
forinc(i,1,n-1){
a[i]=distrib(gen); if(a[i]==0) in++;
}
}
//forinc(i,0,n-1) cout << a[i] << " "; cout << nn;
Stt=(Stt and (count_mushrooms(n)==in));
ANS=max(ANS,cnt);
if(!Stt) cout << "wa3" << nn;
//cout << (count_mushrooms(n)==in) << endl;
//cout << count_mushrooms(n) << " " << in;
}
cout << ANS << nn << Stt;
int n; cin >> n; in=0; forinc(i,0,n-1){
cin >> a[i]; if(a[i]==0) in++;
}
cout << count_mushrooms(n) << " " << in;
}
*/
