Compilare: main.cpp: In function 'void remove_edge(int, int, int)': main.cpp:51:13: warning: comparison of integer expressions of different signedness: 'int' and '__gnu_pbds::detail::bin_search_tree_set<int, __gnu_pbds::null_type, std::less<int>, __gnu_pbds::detail::tree_traits<int, __gnu_pbds::null_type, std::less<int>, __gnu_pbds::tree_order_statistics_node_update, __gnu_pbds::rb_tree_tag, std::allocator<char> >, std::allocator<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 51 | if (cnt <= s[id].size() / 2) { | ~~~~^~~~~~~~~~~~~~~~~~~