vector <int> longest_trip(int N, int D){
vector <int> path, clique, used(N);
for (int i = 0; i <= 2; i++){
for (int j = 0; j < i; j++){
if (are_connected({i}, {j})){
path = {i, j};
used[i] = used[j] = 1;
break;
}
}
if (!path.empty()) break;
}
pair<int, int> non_edge{-1, -1};
for (int v = 0; v < N; v++){
if (used[v]) continue;
int P = path.size();
int st = path[0], fin = path[P-1];
if (!are_connected(path, {v})){
clique.push_back(v);
continue;
}
if (are_connected({st}, {v})){
reverse(path.begin(), path.end());
path.push_back(v);
continue;
}
else if (non_edge.second == -1) non_edge = {st, v};
if (P > 1 && are_connected({fin}, {v})){
path.push_back(v);
continue;
}
vector <int> check;
if (non_edge.second != -1 && non_edge.second != v){
check = {non_edge.first, non_edge.second};
}
else{
for (int i = 1; i < P-1; i++) check.push_back(path[i]);
}
for (int u : check){
if (are_connected({u}, {v})){
int i = -1;
for (int ii = 0; ii < P; ii++)
if (path[i] == u) i = ii;
vector <int> npath;
for (int j = 0; j < P; j++)
npath.push_back(path[(j+i+1)%P]);
npath.push_back(v);
path = npath;
break;
}
}
}
assert(path.size() + clique.size() == N);
if (path.size() >= clique.size()) return path;
else return clique;
}
Compilation message
longesttrip.cpp:1:1: error: 'vector' does not name a type
1 | vector <int> longest_trip(int N, int D){
| ^~~~~~
