#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;
std::vector<int> longest_trip(int n, int d)
{
vector<int> A;
vector<int> B;
A.push_back(0);
for (int i = 1; i < n; i++)
{
if(are_connected({i}, {A.back()})) A.push_back(i);
else if(B.size()==0 || are_connected({i}, {B.back()})) B.push_back(i);
else {
for (int x = B.size()-1; x >= 0; x--) A.push_back(B[x]);
B.clear();
B.push_back(i);
}
}
if(A.size()<B.size()) swap(A,B);
vector<int> outp;
if(B.size()==0 || !are_connected({A},{B})) return A;
int aN=A.size(), bN=B.size();
if(are_connected({A[aN-1]}, {B[bN-1]})){
for (int i = 0; i < aN; i++) outp.push_back(A[i]);
for (int i = bN-1; i >= 0; i--) outp.push_back(B[i]);
// cout << "method1\n";
}else if(are_connected({A[aN-1]}, {B[0]})){
for (int i = 0; i < aN; i++) outp.push_back(A[i]);
for (int i = 0; i < bN; i++) outp.push_back(B[i]);
//cout << A.size() << " " << B.size() << " method2\n";
}else if(are_connected({A[0]}, {B[bN-1]})){
for (int i = aN-1; i >= 0; i--) outp.push_back(A[i]);
for (int i = bN-1; i >= 0; i--) outp.push_back(B[i]);
//cout << "method3\n";
}else if(are_connected({A[0]}, {B[0]})){
for (int i = aN-1; i >= 0; i--) outp.push_back(A[i]);
for (int i = 0; i < bN; i++) outp.push_back(B[i]);
//cout << "method4\n";
}else{
int aConnect=0;
int l=0, r=aN-1;
while(l<r)
{
int mid=(l+r)/2;
vector<int> vec;
for (int i = l; i <= mid; i++) vec.push_back(A[i]);
if(are_connected(vec, B)){
aConnect=mid;
r=mid-1;
}else{
l=mid+1;
}
}
int bConnect=0;
l=0, r=bN-1;
while(l<r)
{
int mid=(l+r)/2;
vector<int> vec;
for (int i = l; i <= mid; i++) vec.push_back(B[i]);
if(are_connected(vec, {A[aConnect]})){
bConnect=mid;
r=mid-1;
}else{
l=mid+1;
}
}
for (int r = aConnect+1; r < aN; r++) outp.push_back(A[r]);
for (int r = 0; r <= aConnect; r++) outp.push_back(A[r]);
for (int r = bConnect; r < bN; r++) outp.push_back(B[r]);
for (int r = 0; r < bConnect; r++) outp.push_back(B[r]);
//cout << "methodLast\n";
}
return outp;
}
