Compilare: user.cpp: In function ‘long int add(long int, long int, long int, long int)’: user.cpp:18:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘long int addCanguri(long int)’: user.cpp:30:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<st[k].size();i++) ^ user.cpp:32:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘long int dellCanguri(long int)’: user.cpp:36:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<fn[k].size();i++) ^ user.cpp:38:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^