Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:23:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[nod].size(); i++) ^ user.cpp:5:11: warning: unused variable ‘first’ [-Wunused-variable] #define x first ^ user.cpp:21:12: note: in expansion of macro ‘x’ int i, x; ^ user.cpp: In function ‘int main()’: user.cpp:62:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<sol[i].size(); j++) ^