https://leetcode.com/problems/rotate-function/

rotate-function.java

class Solution {
    public int maxRotateFunction(int[] A) {
        int sum = 0;
        int F = 0;
        int len = A.length;
        for (int i = 0; i < len; i++) {
            sum += A[i];
            F += i * A[i];
        }
        
        int res = F;
        for (int i = 1; i < len; i++) {
            F = F + sum - len * A[len - i];
            res = Math.max(res, F);
        }
        return res;
    }
}