#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> rng(vector<int>& a, int l, int r) {
vector<int> res;
for(int i = l; i <= r; ++i) res.push_back(a[i]);
return res;
}
std::vector<int> longest_trip(int N, int D)
{
if(D == 3) {
vector<int> res(N);
for(int i = 0; i < N; ++i)
res[i] = i;
return res;
}
if(D == 2) {
vector<int> res = {0};
for(int i = 1; i < N; ++i) {
if(are_connected({res.back()}, {i})) {
res.push_back(i);
continue;
}
if(i == 1) {
res.push_back(i + 1);
res.push_back(i);
i++;
continue;
}
res.insert(res.begin(), i);
}
return res;
}
vector<vector<int> > all;
for(int i = 0; i < N; ++i) {
all.push_back({i});
}
bool la = 0;
while(all.size() >= 3) {
int sz = all.size();
if(la == 0) {
if(are_connected({all[sz - 1].back()}, {all[sz - 2].back()})) {
reverse(all[sz - 1].begin(), all[sz - 1].end());
for(auto x : all[sz - 1]) all[sz - 2].push_back(x);
all.pop_back();
la = 0;
continue;
}
la = 1;
}
if(are_connected({all[sz - 1].back()}, {all[sz - 3].back()})) {
reverse(all[sz - 1].begin(), all[sz - 1].end());
for(auto x : all[sz - 1]) all[sz - 3].push_back(x);
all.pop_back();
la = 0;
continue;
}
reverse(all[sz - 2].begin(), all[sz - 2].end());
for(auto x : all[sz - 2]) all[sz - 3].push_back(x);
swap(all[sz - 1], all[sz - 2]);
all.pop_back();
la = 0;
}
if(are_connected({all[0].back()}, {all[1].back()})) {
reverse(all[1].begin(), all[1].end());
for(auto x : all[1]) all[0].push_back(x);
return all[0];
}
if(are_connected({all[0].back()}, {all[1][0]})) {
for(auto x : all[1]) all[0].push_back(x);
return all[0];
}
if(are_connected({all[0][0]}, {all[1][0]})) {
reverse(all[0].begin(), all[0].end());
for(auto x : all[1]) all[0].push_back(x);
return all[0];
}
if(are_connected({all[0][0]}, {all[1].back()})) {
reverse(all[0].begin(), all[0].end());
reverse(all[1].begin(), all[1].end());
for(auto x : all[1]) all[0].push_back(x);
return all[0];
}
int l0 = 0, r0 = (int)all[0].size() - 1;
int l1 = 0, r1 = (int)all[1].size() - 1;
// for(auto& x : all[0]) cout<<x<<' ';
// cout<<'\n';
// for(auto& x : all[1]) cout<<x<<' ';
// cout<<'\n';
if(are_connected(rng(all[0], l0, r0), rng(all[1], l1, r1)) == 0) {
if(all[0].size() > all[1].size()) return all[0];
return all[1];
}
while(l0 != r0 || l1 != r1) {
if(l0 != r0) {
int m = (l0 + r0) >> 1;
if(are_connected(rng(all[0], l0, m), rng(all[1], l1, r1))) {
r0 = m;
} else {
l0 = m + 1;
}
continue;
}
int m = (l1 + r1) >> 1;
if(are_connected(rng(all[0], l0, r0), rng(all[1], l1, m))) {
r1 = m;
} else {
l1 = m + 1;
}
}
vector<int> res;
for(int i = 1; i <= all[1].size(); ++i) {
res.push_back(all[1][(i + l1) % all[1].size()]);
}
for(int i = 0; i < all[0].size(); ++i) {
res.push_back(all[0][(i + l0) % all[0].size()]);
}
return res;
}
