Find maximum value of Sum with only rotations on given array allowed in C.

maxRotatedArraySum.c

int get_max(int x, int y) {
    if (x > y)
        return x;
    return y;
}

int get_sum(int * arr, int arr_size) {
    int sum = 0, index;
    for(index = 0; index < arr_size; index++) {
        sum += index * arr[index];
    }
    return sum;
}

int max_sum(int * arr, int arr_size) {
    // Time complexity of this solution is O(n2).
    int index, j, temp, max = 0;
    for (index = 0; index < arr_size; index++) {
        temp = arr[0];
        for (j = 1; j < arr_size; j++) {
            arr[j - 1] = arr[j];
        }
        arr[arr_size - 1] = temp;
        max = get_max(get_sum(arr, arr_size), max);
    }
    return max;
}