foo.cc: In function ‘int main()’:
foo.cc:7:36: error: expected ‘;’ before ‘int’
    7 |         for(int i=1;i<=n;i++)a[i=1]
      |                                    ^
      |                                    ;
    8 |         int i=0;
      |         ~~~                         
foo.cc:11:17: error: ‘i’ was not declared in this scope
   11 |                 i=i%n+1;
      |                 ^