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:101:34: 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:126:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[a].size(); i++) ^