泛型算法（八）之旋转算法

1、rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last)：等效于循环左移序列，使得迭代器middle所指的元素成为首元素。

    std::vector<int> c;
    c.reserve(10);
    //向c中添加元素
    for (int i = 0; i < 10; i++)
    {
        c.push_back(i);
    }
    //旋转c中的元素，使得数组下标为5的元素成为首元素
    std::rotate(c.begin(), c.begin() + 5, c.end());
    //输出c
    for (auto var : c)
    {
        std::cout << var << ",";
    }
    //打印结果：5,6,7,8,9,0,1,2,3,4        

2、rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result)：等效于循环左移序列并复制到新的存储空间，使得迭代器middle所指的元素成为首元素。

    std::vector<int> c;
    std::vector<int> result;
    c.reserve(10);
    result.resize(10);
    //向c中添加元素
    for (int i = 0; i < 10; i++)
    {
        c.push_back(i);
    }
    //复制c的旋转到result中，c本身没有改变
    std::rotate_copy(c.begin(), c.begin() + 5, c.end(), result.begin());
    //输出result
    for (auto var : result)
    {
        std::cout << var << ",";
    }
    //打印结果：5,6,7,8,9,0,1,2,3,4