/in/foo.cc: In function 'int main()':
/in/foo.cc:11:15: error: 'i' was not declared in this scope
   11 |         int a[i]={0},n=0;
      |               ^
/in/foo.cc:13:17: error: 'a' was not declared in this scope
   13 |                 a[i]=x%2;
      |                 ^