Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:22:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[nod].size(); i++) ^ user.cpp:8:11: warning: unused variable ‘first’ [-Wunused-variable] #define x first ^ user.cpp:20:11: note: in expansion of macro ‘x’ int i,x; ^ user.cpp: In function ‘int main()’: user.cpp:61:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < sol[i].size(); j++) ^