Compilare: user.c: In function ‘main’: user.c:69:9: warning: unused variable ‘i’ [-Wunused-variable] int i, ^ user.c: In function ‘read’: user.c:11:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r", stdin); ^ user.c:13:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&num); ^ user.c:19:36: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] for(i = 0; i < num; ++i) scanf("%d", (arr+i)); ^ user.c: In function ‘write’: user.c:30:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT, "w", stdout); ^ user.c: In function ‘main’: user.c:74:9: warning: ‘arr’ is used uninitialized in this function [-Wuninitialized] arr = read( arr, &n ); ^