------
## 最终结论
```python
def sort_array(array):
    if len(array) <= 1:
        return array.copy()
    
    first_element = array[0]
    last_element = array[-1]
    total = first_element + last_element
    
    if total % 2 == 0:
        return sorted(array, reverse=True)
    else:
        return sorted(array)
```