Compilare: user.cpp:73:11: warning: multi-character character constant [-Wmultichar] fout << '-1'; ^ user.cpp: In function ‘void euler(int)’: user.cpp:27:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (urm = 0; urm < g[nod].size(); urm++) ^ user.cpp:32:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[viz[nod][urm]].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:48:6: warning: unused variable ‘a’ [-Wunused-variable] int a, b; ^ user.cpp:48:9: warning: unused variable ‘b’ [-Wunused-variable] int a, b; ^