Compilare: user.c:3:1: warning: data definition has no type or storage class [enabled by default] vector[1000001]; ^ user.c:3:1: warning: type defaults to ‘int’ in declaration of ‘vector’ [enabled by default] user.c:5:1: warning: return type defaults to ‘int’ [enabled by default] main(){ ^ user.c: In function ‘main’: user.c:7:8: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("magicnum.in", "r", stdin); ^ user.c:8:8: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("magicnum.out", "w", stdout); ^ user.c:12:6: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a); ^ user.c:13:6: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b); ^