#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
vector<int> longest_trip(int N, int D) {
// check if single component
// if not, each component is clique, problem is then find largest component
// otherwise, one component,
// start with one node and keep trying to extend path by randomly querying
// if gets stuck, that means past must be a clique, done
int calls = 0;
auto my_are_connected = [&](vector<int> a, vector<int> b) {
calls ++;
assert(calls <= 32460);
return are_connected(a, b);
};
bool found = 0;
vector<int> answer;
using vi = vector<int>;
auto halves = [&](vector<int> v) -> pair<vi, vi> {
int m = v.size() / 2;
return {{v.begin(), v.begin()+m}, {v.begin()+m, v.end()}};
};
vector<int> path = {0};
vector<int> left(N-1);
vector<int> clique;
iota(left.begin(), left.end(), 1);
while (left.size() || !clique.empty()) {
random_shuffle(left.begin(), left.end());
auto locate = [&](vector<int> src, vector<int> dest) -> int {
while (src.size() != 1) {
auto [a, b] = halves(src);
if (my_are_connected(a, dest)) src = a;
else src = b;
}
return src[0];
};
// auto add = [&](int nxt) -> void {
// path.push_back(nxt);
// for (int x : clique[nxt]) path.push_back(x);
// };
int v = path.back();
if (!clique.empty()) {
// cerr << "a";
if (my_are_connected(clique, {v})) {
int b = locate(clique, {v});
clique.erase(find(clique.begin(), clique.end(), b));
path.push_back(b);
for (int x : clique) path.push_back(x);
clique.clear();
continue;
}
}
while (!left.empty()) {
int nxt = left.back(); left.pop_back();
// cerr << left.size() + clique.size() << " ";
if (!my_are_connected({nxt}, {v})) {
clique.push_back(nxt);
}
else {
path.push_back(nxt);
break;
}
}
if (left.empty() && !clique.empty()) {
left = clique;
if (!my_are_connected(path, left)) {
if (path.size() > left.size()) return path;
else return left;
}
int a = locate(path, left);
int b = locate(left, {a});
vector<int> ans = left;
ans.erase(find(ans.begin(), ans.end(), b));
ans.push_back(b);
int j = find(path.begin(), path.end(), a) - path.begin();
if (j == 0) {
for (int x : path) {
ans.push_back(x);
}
}
else {
for (int i = j; i >= 0; --i) {
ans.push_back(path[i]);
}
for (int i = path.size()-1; i > j; --i) {
ans.push_back(path[i]);
}
}
// for (int i = 1; i < ans.size(); ++i) {
// assert(my_are_connected({ans[i]}, {ans[i-1]}));
// }
return ans;
}
}
for (int i = 1; i < path.size(); ++i) {
assert(my_are_connected({path[i]}, {path[i-1]}));
}
return path;
}
