Compilare: user.c: In function 'testromb': user.c:62: warning: implicit declaration of function 'abs' user.c:58: warning: unused variable 'j' user.c:58: warning: unused variable 'i' user.c: In function 'main': user.c:176: warning: implicit declaration of function 'system' user.c:167: warning: unused variable 'j' user.c:167: warning: unused variable 'i' user.c:177: warning: control reaches end of non-void function user.c: In function 'max': user.c:80: warning: 'lf' may be used uninitialized in this function