#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> longest_trip(int N, int D) {
vector<int> trip1(1, 0), trip2(1, 1);
int state = 2;
int num1;
for (int i = 2; i < N; i++) {
if (state == 0) {
if (are_connected(vector<int>(1, trip2.front()), vector<int>(1, i)))
trip2.push_back(i);
else
trip1.insert(trip1.begin() + num1, i);
state = 2;
} else if (state == 1) {
if (are_connected(vector<int>(1, trip1.back()), vector<int>(1, i)))
trip1.push_back(i);
else
trip2.push_back(i);
state = 2;
} else if (state == 2) {
bool b1 = are_connected(vector<int>(1, trip1.back()), vector<int>(1, i)),
b2 = are_connected(vector<int>(1, trip2.back()), vector<int>(1, i));
if (b1 && b2) {
reverse(trip2.begin(), trip2.end());
trip1.push_back(i);
for (auto a : trip2) trip1.push_back(a);
trip2.clear();
if (i == N - 1) return trip1;
i++;
trip2.push_back(i);
} else if (b1) {
trip1.push_back(i);
state = 1;
} else if (b2) {
trip2.push_back(i);
state = 1;
} else {
num1 = trip1.size();
reverse(trip2.begin(), trip2.end());
for (auto a : trip2) trip1.push_back(a);
trip2.clear();
trip2.push_back(i);
state = 0;
}
}
}
if (trip2.empty()) return trip1;
if (are_connected(trip1, trip2)) {
// vector<int> vi, vi2;
// if (trip1.size() != 1)
// vi.push_back(trip1.front()), vi.push_back(trip1.back());
// else
// vi.push_back(trip1.front());
// if (trip2.size() != 1)
// vi2.push_back(trip2.front()), vi2.push_back(trip2.back());
// else
// vi2.push_back(trip2.front());
// if (are_connected(vi, vi2)) {
// while (1) {
// }
// }
// if (trip1.size() != 1) {
// if (!are_connected(vector<int>(1, trip1.front()),
// vector<int>(1, trip1.back())))
// while (1) {
// }
// }
// if (trip2.size() != 1) {
// if (!are_connected(vector<int>(1, trip2.front()),
// vector<int>(1, trip2.back())))
// while (1) {
// }
// }
vector<int> vi, vi2;
if (trip1.size() != 1)
vi.push_back(trip1.front()), vi.push_back(trip1.back());
else
vi.push_back(trip1.front());
if (trip2.size() != 1)
vi2.push_back(trip2.front()), vi2.push_back(trip2.back());
else
vi2.push_back(trip2.front());
if (are_connected(vi, vi2)) {
vector<int> ans;
if (are_connected(vector<int>(1, trip1.front()),
vector<int>(1, trip2.front())))
reverse(trip1.begin(), trip1.end());
else if (are_connected(vector<int>(1, trip1.front()),
vector<int>(1, trip2.back())))
trip1.swap(trip2);
else if (are_connected(vector<int>(1, trip1.back()),
vector<int>(1, trip2.front()))) {
} else if (are_connected(vector<int>(1, trip1.back()),
vector<int>(1, trip2.back())))
reverse(trip2.begin(), trip2.end());
for (auto a : trip1) ans.push_back(a);
for (auto a : trip2) ans.push_back(a);
return ans;
}
int l = 0, r = int(trip1.size()) - 1;
while (l < r) {
int mid = (l + r) / 2;
vector<int> tmp;
for (int i = l; i <= mid; i++) tmp.push_back(trip1[i]);
if (are_connected(tmp, trip2))
r = mid;
else
l = mid + 1;
}
int firstone = l;
l = 0, r = int(trip2.size()) - 1;
while (l < r) {
int mid = (l + r) / 2;
vector<int> tmp;
for (int i = l; i <= mid; i++) tmp.push_back(trip2[i]);
if (are_connected(tmp, vector<int>(1, trip1[firstone])))
r = mid;
else
l = mid + 1;
}
int secondone = l;
vector<int> ans;
for (int i = firstone + 1; i < trip1.size(); i++) ans.push_back(trip1[i]);
for (int i = 0; i <= firstone; i++) ans.push_back(trip1[i]);
for (int i = secondone; i < trip2.size(); i++) ans.push_back(trip2[i]);
for (int i = 0; i < secondone; i++) ans.push_back(trip2[i]);
return ans;
}
if (trip1.size() < trip2.size()) trip1.swap(trip2);
return trip1;
}
