Compilare: main.cpp: In function 'int main()': main.cpp:63:25: warning: loop variable 'neighbor' creates a copy from type 'const std::pair<int, int>' [-Wrange-loop-construct] 63 | for (const auto neighbor : neighbors) { | ^~~~~~~~ main.cpp:63:25: note: use reference type to prevent copying 63 | for (const auto neighbor : neighbors) { | ^~~~~~~~ | &