highway.cpp: In function 'void dfs(int, int, int)':
highway.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0; i < adj[u].size(); i++){
~~^~~~~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:38:12: warning: unused variable 'a' [-Wunused-variable]
long long a = A, b = B;
^
highway.cpp:38:19: warning: unused variable 'b' [-Wunused-variable]
long long a = A, b = B;
^
highway.cpp:39:12: warning: unused variable 'sqrtn' [-Wunused-variable]
long long sqrtn = sqrt(n), sm = ask(w);
^~~~~
/tmp/cczd7YFI.o: In function `find_pair(int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, int, int)':
highway.cpp:(.text+0x5b3): undefined reference to `ask(std::vector<int, std::allocator<int> >)'
highway.cpp:(.text+0x778): undefined reference to `ask(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status