#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
vector <int> adj[256], tree[256];
bool vis[256];
struct DSU {
int p[256], sze[256];
void init (int n) {
for (int i = 0; i < n; i++) {
p[i] = i; sze[i] = 1;
}
}
int find (int x) {
return p[x] == x ? x : p[x] = find(p[x]);
}
bool merge (int a, int b) {
a = find(a), b = find(b);
if (a == b) return 0;
if (sze[a] > sze[b]) swap(a, b);
sze[b] += sze[a]; p[a] = b;
return 1;
}
} cur;
vector <int> x;
int p[256];
void dfs (int pos) {
vis[pos] = 1; x.push_back(pos);
for (auto j : adj[pos]) {
if (vis[j]) continue;
tree[pos].push_back(j);
p[j] = pos;
dfs(j);
}
}
int get (int x) {
if (tree[x].empty()) return x;
return get(tree[x][0]);
}
vector <int> longest_trip (int n, int d) {
for (int i = 0; i < n; i++) adj[i].clear(), tree[i].clear();
memset(p, -1, sizeof(p));
cur.init(n);
for (int i = 0; i < n - 1; i++) {
for (int j = i + 1; j < n; j++) {
if (are_connected({i}, {j})) {
adj[i].push_back(j);
adj[j].push_back(i);
cur.merge(i, j);
}
}
}
bool flag = 0;
for (int i = 0; i < n - 1; i++) {
for (int j = i + 1; j < n; j++) {
flag |= cur.merge(i, j);
}
}
if (flag) {
memset(vis, 0, sizeof(vis));
vector <int> ret;
for (int i = 0; i < n; i++) {
if (!vis[i]) {
x.clear(); dfs(i);
if ((int)x.size() > (int)ret.size()) ret = x;
}
}
return ret;
}
memset(vis, 0, sizeof(vis));
x.clear(); dfs(0);
int pos = -1;
for (int i = 0; i < n; i++) {
if ((int)tree[i].size() == 2) {
assert(pos == -1);
pos = i;
}
}
if (pos == -1) return x;
int u = get(tree[pos][0]), v = get(tree[pos][1]);
if (p[pos] != -1 && find(adj[p[pos]].begin(), adj[p[pos]].end(), u) == adj[p[pos]].end()) swap(u, v);
auto g = find(x.begin(), x.end(), pos) - x.begin();
x.erase(x.begin() + g);
g = find(x.begin(), x.end(), u) - x.begin(); g++;
x.insert(x.begin() + g, pos);
//assert((int)x.size() == n);
for (int i = 1; i < (int)x.size(); i++) {
auto u = find(adj[x[i]].begin(), adj[x[i]].end(), x[i - 1]);
assert(u != adj[x[i]].end());
}
return x;
}
