1
class Solution {
2
 public:
3
  int maxRotateFunction(vector<int> &A) {
4
    long sum = 0, fn = 0;
5
    int len = A.size();
6
    for (int i = 0; i < len; i++) {
7
      sum += A[i];
8
      fn += (i * A[i]);
9
    }
10

11
    long l = 1, r;
12
    long newfn = fn;
13

14
    while (l < len) {
15
      r = l + len - 1;
16

17
      long removed = (l - 1) * A[l - 1];
18
      long added = r * A[r % len];
19

20
      newfn = newfn - removed + added - sum;
21

22
      fn = max(fn, newfn);
23

24
      l++;
25
    }
26

27
    return (int)fn;
28
  }
29
};