Compilare: main.cpp: In function 'void dfs(int)': main.cpp:48:31: warning: loop variable 'elem' of type 'const std::pair<int, int>&' binds to a temporary constructed from type 'std::pair<const int, int>' [-Wrange-loop-construct] 48 | for (const pair<int,int>& elem: G[node]) { | ^~~~ main.cpp:48:31: note: use non-reference type 'const std::pair<int, int>' to make the copy explicit or 'const std::pair<const int, int>&' to prevent copying