解决方法
reverse_copy实际上以相反的顺序放置元素.
1 2 3 4 5 - > 5 4 3 2 1
copy_backward只是向后复制元素,但保留它们的相对顺序.
1 2 3 4 5
首先复制5,但放在最后一个位置.所以你的输出仍然是：
1 2 3 4 5
http://en.cppreference.com/w/cpp/algorithm/copy_backward
Copies the elements from the range,defined by [first,last),to another range ending at d_last. The elements are copied in reverse order (the last element is copied first),but their relative order is preserved.
http://en.cppreference.com/w/cpp/algorithm/reverse_copy
Copies the elements from the range [first,last) to another range beginning at d_first in such a way that the elements in the new range are in reverse order.
