Compilare: user.c: In function 'f': user.c:17: warning: 'return' with no value, in function returning non-void user.c:30: warning: 'return' with no value, in function returning non-void user.c:11: warning: unused variable 'i' user.c:43: warning: control reaches end of non-void function user.c:30: warning: 'nr1' is used uninitialized in this function user.c:30: warning: 'nr0' is used uninitialized in this function