text: This is where it differs from Kadane 's  algorithm. We use modular arithmetic to  find next element.
code: max_ending_here = max_ending_here + a [ i % n ] ; if ( max_so_far < max_ending_here ) max_so_far = max_ending_here ; if ( max_ending_here < 0 ) max_ending_here = 0 ; } return max_so_far ; }