/in/foo.c: In function 'main':
/in/foo.c:7:2: error: variable-sized object may not be initialized
  int arr[n]={0};
  ^~~
/in/foo.c:7:14: warning: excess elements in array initializer
  int arr[n]={0};
              ^
/in/foo.c:7:14: note: (near initialization for 'arr')