Java 中的vector和list的区别和使用实例详解

template <class T>class Vector{public:  typedef T* Iterator;  typedef const T* Iterator;  Vector()    :_start(NULL)    ,_finish(NULL)    ,_endOfStorage(NULL)  {}  void template<class T>  PushBack(const T& x)  {    Iterator end = End();    Insert(end, x);  }  void Insert(Iterator& pos, const T& x)  {    size_t n = pos - _start;    if (_finish == _endOfStorage)    {      size_t len = Capacity() == 0 ? 3 :  Capacity()*2;      Expand(len);    }    pos = _start+n;    for (Iterator end = End(); end != pos; --end)    {      *end = *(end-1);    }    *pos = x;    ++_finish;  }  Iterator End()  {    return _finish;  }  Iterator Begin()  {    return _start;  }  void Resize(size_t n, const T& val = T())//用Resize扩容时需要初始化空间，并且可以缩小容量  {    if (n < Size())    {      _finish = _start+n;    }    else    {      Reserve(n);      size_t len = n-Size();      for (size_t i = 0; i < len; ++i)      {        PushBack(val);      }    }  }  void Reserve(size_t n)//不用初始化空间，直接增容  {    Expand(n);  }  inline size_t Size()  {    return _finish-_start;  }  inline size_t Capacity()  {    return _endOfStorage-_start;  }  void Expand(size_t n)  {    const size_t size = Size();    const size_t capacity = Capacity();    if (n > capacity)    {      T* tmp = new T[n];      for (size_t i = 0; i < size; ++i)      {        tmp[i] = _start[i];      }      delete[] _start;      _start = tmp;      _finish = _start+size;      _endOfStorage = _start+n;    }  }  T& operator[](size_t pos)  {    assert(pos < Size());    return _start[pos];  }  const T& operator[](size_t pos) const  {    assert(pos < Size());    return _start[pos];  }protected:  Iterator _start; //指向第一个元素所在节点  Iterator _finish; //指向最后一个元素所在节点的下一个节点  Iterator _endOfStorage; //可用内存空间的末尾节点};