#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-1; i+=2)
{
if(are_connected({i},{i+1})){
if(are_connected({i}, {A.back()})){
A.push_back(i);
A.push_back(i+1);
}
else if(B.size()==0 || are_connected({i}, {B.back()})){
B.push_back(i);
B.push_back(i+1);
}
else {
for (int x = B.size()-1; x >= 0; x--) A.push_back(B[x]);
B.clear();
B.push_back(i);
B.push_back(i+1);
}
}else{
if(are_connected({i}, {A.back()})){
A.push_back(i);
if(B.size()==0 || are_connected({i}, {B.back()})){
for (int x = B.size()-1; x >= 0; x--) A.push_back(B[x]);
B.clear();
}
B.push_back(i+1);
}
else if(B.size()==0 || are_connected({i}, {B.back()})){
B.push_back(i);
if(are_connected({i}, {A.back()})){
for (int x = A.size()-1; x >= 0; x--) B.push_back(A[x]);
A.clear();
B.push_back(i+1);
swap(A,B);
}else{
A.push_back(i+1);
}
}
else {
A.push_back(i+1);
for (int x = B.size()-1; x >= 0; x--) A.push_back(B[x]);
B.clear();
B.push_back(i);
}
}
}
if(n%2==0){
int i=n-1;
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(aN==1){
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 if(bN==1){
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[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 if(are_connected({A[0] ,A[aN]}, {B[0] ,B[bN-1]}) {
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 l=0;
int 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)){
r=mid;
}else{
l=mid+1;
}
}
int aConnect=l;
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({A[aConnect]}, vec)){
r=mid;
}else{
l=mid+1;
}
}
int bConnect=l;
for (int i = aConnect+1; i < aN; i++) outp.push_back(A[i]);
for (int i = 0; i <= aConnect; i++) outp.push_back(A[i]);
for (int i = bConnect; i < bN; i++) outp.push_back(B[i]);
for (int i = 0; i < bConnect; i++) outp.push_back(B[i]);
//cout << "methodLast\n";
}
return outp;
}
//
Compilation message
longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:90:58: error: expected ';' before '{' token
90 | else if(are_connected({A[0] ,A[aN]}, {B[0] ,B[bN-1]}) {
| ^~
| ;
longesttrip.cpp:109:5: error: expected primary-expression before 'else'
109 | else{
| ^~~~
longesttrip.cpp:108:6: error: expected ')' before 'else'
108 | }
| ^
| )
109 | else{
| ~~~~
longesttrip.cpp:90:12: note: to match this '('
90 | else if(are_connected({A[0] ,A[aN]}, {B[0] ,B[bN-1]}) {
| ^
longesttrip.cpp:8:17: warning: control reaches end of non-void function [-Wreturn-type]
8 | vector<int> B;
| ^
