C++如何实现动态线性表

#include <iostream>
#include<assert.h>
#include<stdio.h>
#include<string.h>
//用typedef定义int为存储类型，想更改直接更改这一句即可。
typedef int DataType;

class Vector
{
public:
  //构造函数。
  Vector()
  {
    _first = new DataType[3];
    _finish = _first;
    _endofstorage = _first + 3;
  }
  //拷贝构造
  Vector(const Vector& v)
  {
    _first = new DataType[v.Size()];
    memmove(_first, v._first, v.Size()*sizeof(DataType));
    _finish = _first + v.Size() ;
    _endofstorage = _finish ;
  }
  //赋值运算符的重载
  Vector& operator=(Vector v);
  //析构函数
  ~Vector()
  {
    delete[] _first;
  }
  //顺序表的有效长度
  size_t Size() const
  {
    return _finish - _first ;
  }
  //顺序表的容量
  size_t Capacity() const
  {
    return _endofstorage - _first ;
  }
  //扩容顺序表
  void Expand(size_t n);
  //尾插
  void PushBack(DataType x);
  //截取容量
  void Reserve(size_t n);
  //尾删
  void PopBack();
  //任意位置插入
  void Insert(size_t pos, DataType x);
  //任意位置删除
  void Erase(size_t pos);
  //查找元素
  size_t Find(DataType x);
  //打印当前顺序表
  void Print();
private:
  //指向第一个元素的指针
  DataType* _first;
  //指向最后一个有效元素的下一个位置
  DataType* _finish;
  //顺序表容量的下一个位置
  DataType* _endofstorage;
};

#include"Vector_List1.h"

  //赋值运算符的重载可以使用传值的方式进行
  //在传值的时候默认调用了拷贝构造函数，进行了深拷贝
  //而当前这个传入的v就是我们想要的赋值之后的结果
  //将当前的顺序表与顺序表v一交换，就可以不用再自己实现深拷贝
  Vector& Vector::operator=(Vector v)
  {
    size_t size = v.Size();
    DataType *tmp = v._first;
    v._first = _first;
    _first = tmp;
    _finish = _first + size;
    _endofstorage = _finish;
    return *this;
  }
  void Vector::Expand(size_t n)
  {
    DataType *tmp = new DataType[n];
    size_t size = Size();
    memmove(tmp, _first, Size()*sizeof(DataType));
    delete[] _first;
    _first = tmp;
    _finish = _first + size;
    _endofstorage = _first + n;
  }
  void Vector::PushBack(DataType x)
  {
    if (_finish > _endofstorage)
      Expand(2 * Capacity());
    *_finish = x;
    _finish++;
  }
  void Vector::PopBack()
  {
    assert(_first < _finish);
    _finish--;
  }
  void Vector::Insert(size_t pos, DataType x)
  {
    assert(pos<Size());
    if(_finish >= _endofstorage)
      Expand(2*Capacity());
    memmove(_first+pos+1,_first+pos,Size()-pos+1);
    *(_first+pos) = x;
  }
  void Vector::Erase(size_t pos)
  {
    assert(pos<Size());
    memmove(_first+pos,_first+pos+1,(Size()-pos-1)*sizeof(DataType));
    _finish--;
  }
  size_t Vector::Find(DataType x)
  {
    DataType *tmp = _first;
    while(tmp != _finish)
    {
      if(*tmp == x)
        return tmp-_first;
      else
        tmp++;
    }
    return -1;
  }
  //截取n个字符
  void Vector::Reserve(size_t n)
  {
    //如果n<capacity,则什么都不做，将其容量降为size与n之间的最大值
    //会改变capacity,不会改变size，若n>capacity扩容，
    if(n<Capacity())
    {
      _endofstorage = _first + ( n > Size() &#63; n : Size());
      return;
    }
    else if(n>Capacity())
    {
      Expand(n);
      return;
    }
    else
      return;
  }   
  void Vector::Print()
  {
    DataType *tmp = _first;
    while (tmp != _finish)
    {
      printf("%d ", *tmp);
      tmp++;
    }
    printf("\n");
  }
int main()
{
  Vector v;
  Vector v1(v);
  v.PushBack(1);
  v.PushBack(2);
  v.PushBack(3);
  v.PushBack(4);
  v.PushBack(5);
  v.PushBack(6);
  v.Print();
  v1 = v;
  v1.Print();
  v1.Erase(2);
  v1.Print();
  size_t ret = v1.Find(3);
  printf("%lu\n",ret);
  ret = v1.Find(2);
  printf("%lu\n",ret);
  ret = v1.Find(5);
  printf("%lu\n",ret);
  v1.Reserve(3);
  v1.Print();
  return 0;
}