Compilare: user.cpp: In function ‘int read()’: user.cpp:27:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘void toposort(int)’: user.cpp:80:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();i++) ^ user.cpp: In function ‘bool con(int, int)’: user.cpp:105:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[a].size();i++) ^