Compilare: user.c: In function 'hash': user.c:35: warning: suggest parentheses around + or - inside shift user.c:35: warning: suggest parentheses around + or - inside shift user.c: In function 'include': user.c:42: warning: unused variable 'y4' user.c:42: warning: unused variable 'x4' user.c:42: warning: unused variable 'x3' user.c:42: warning: unused variable 'y2' user.c: In function 'init': user.c:27: warning: control reaches end of non-void function