/in/foo.c: In function 'main':
/in/foo.c:6:7: error: array size missing in 'a'
    6 |   int a[];
      |       ^
/in/foo.c:9:35: error: expected ';' before '}' token
    9 |                 scanf ("%d",&a[i])
      |                                   ^
      |                                   ;
   10 |                 };
      |                 ~