For each element of array how much number to be added to make it divisible by K
for ( int j = 0 ; j < n ; j ++ ) if ( ( arr [ j ] % k ) != 0 ) b2 . push_back ( k - ( arr [ j ] % k ) ) ; else b2 . push_back ( 0 ) ; c = 0 ; float mini = INT_MAX ; suml = 0 ; sumr = 0 ; index = -1 ;