Compilare: main.cpp: In function 'int main()': main.cpp:51:9: warning: variable 'l1' set but not used [-Wunused-but-set-variable] int l1, l2, l3; ^~ main.cpp:51:13: warning: variable 'l2' set but not used [-Wunused-but-set-variable] int l1, l2, l3; ^~ main.cpp:51:17: warning: variable 'l3' set but not used [-Wunused-but-set-variable] int l1, l2, l3; ^~ main.cpp: In function 'int dijkstra(std::__cxx11::string, std::__cxx11::string, std::__cxx11::string)': main.cpp:46:1: warning: control reaches end of non-void function [-Wreturn-type] } ^