从向量中读取元素：

1通过下标：

int a[6] = { 1,2,3,4,5,6 };

    vector<int> b(a, a + 4);

    for (int i = 0; i <= b.size() - 1; i++)

        cout << b[i] << " ";

2通过迭代器

int a[6] = { 1,2,3,4,5,6 };

    vector<int> b(a, a + 4);

    for (vector<int>::iterator it = b.begin(); it != b.end(); it++)

        cout << *it << " ";