/in/foo.c: In function 'main':
/in/foo.c:7:5: error: variable-sized object may not be initialized
     int a[n]={0};
     ^~~
/in/foo.c:7:15: warning: excess elements in array initializer
     int a[n]={0};
               ^
/in/foo.c:7:15: note: (near initialization for 'a')