longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:9:27: error: 'are_connected' was not declared in this scope
9 | a[i][j] = a[j][i] = are_connected({i}, {j});
| ^~~~~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
from longesttrip.cpp:1:
longesttrip.cpp:37:28: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
37 | assert(size(ans) == n);
| ~~~~~~~~~~^~~~