用模板类实现顺序表

#pragma once#include<iostream>#include<assert.h>#include<string.h>using namespace std;template<class T>class Vector{private:T* _start;T* _finish;T* _endOfStorage;private://如果容量小于顺序表的大小，则增容void _CheckCapacity(){size_t oldsize = Size();size_t capacity = Capacity();if (Size() >= _capacity)size_t newcapacity = 2 * capacity + 3;//申请新空间T* temp = new T[newCapacity];//拷贝元素memcpy(temp, _start, size*sizeof(T));//释放if (_start){delete[] _start;_start = temp;_finish = _start + newsize;_endOfStorage = _finish;}}public:Vector()//无参构造函数{_start = NULL;_finish = 0;_endOfStorage = 0;}Vector(const T* array, size_t size)//有参构造函数{_start = T[size];_finish = _start + size;_endOfStorage = _start + size;assert(NULL != array);//易出错//memcpy(_start,array,size*sizeof(T));//效率低for (size_t i = 0; i < size; ++i)_start[i] = array[i];}Vector(const Vector& v)//拷贝构造函数:_start(new T[v.Size()]){_size_t size = v.Size();_start = new T[size];for (size_t i = 0; i < size; i++)_start[i] = v[i];_finish = _start + size;_endOfStorage = _finish;}Vector<T>& operator=(const Vector& s)//重载{if (this != &s){T* temp = new T[s._capacity];for (size_t i = 0; i < s._size; i++)temp[i] = s._data[i];delete[] s._data;_data = temp;_size = s._size;_capacity = s._size;}return *this;}~Vector()//析构函数{if (_start != NULL){delete[] _start;}_start = _finish = _endOfStorage = 0;}size_t Size()const//返回顺序表的长度{return _finish-_start;}size_t Capacity()const//返回顺序表的容量{return _endOfStorage-_capacity;}void PushBack(const T& d)//尾插{_CheckCapacity();*_finish++ = d;}void PopBack()//尾删{--_finish;}void Insert(size_t pos, const T& d)//在位置pos处插入数值d{assert(pos <= Size());_CheckCapacity();//搬元素for (size_t i = Size(); i > pos; --i)_start[i] = _start[i-1];/*for (size_t i = Size()-1 ; i >= pos; --i)_data[i+1] = _data[i];*///插入元素d_start[pos] = d;_finish++;}void Erase(size_t pos)//删除位置pos的元素{assert(pos <= Size());for (size_t i = pos; i < Size() - 1; i++)_start[i] = _start[i + 1];_finish--;}bool Empty()const//判空{return 0 == Size();}//实现下标访问T& operator[](size_t index){return _start[index];}const T& operator[](size_t index)const{return _start[index];}//返回顺序表的第一个元素T& Front(){return _start[0];}const T& Front()const{return _start[0];}//返回顺序表的最后一个元素T& Back(){return _start[Size() - 1];}const T& Back()const{return _start[Size() - 1];}void Resize(size_t newsize, const T& d = T())//将顺序表中的元素个数变成newSize{size_t oldsize = Size();if (oldsize >= newsize)_finish = _start + newsize;else if (newsize > oldsize && newsize < Capacity()){for (size_t i = oldsize; i < newsize; i++)_start[i] = d;_finish = _start + newsize;}else{T* temp = newsize;//旧空间的元素搬到新空间for (size_t i = 0; i < oldsize; i++)temp[i] = _start[i];//新空间中多出来的空间放dfor (size_t i = oldsize; i < newsize; i++)temp[i] = d;//释放旧空间delete[] _start;_start = temp;_finish = _start + newsize;_endOfStorage = _finish;}}void clear()//清空{_finish = _start;}void Display()//打印{if (_start == NULL)return;size_t size = Size();size_t capacity = Capacity();for (size_t i = 0; i < size; i++){cout << _start[i] << " ";}cout << endl;}};int main(){int arr[] = { 1, 2, 3, 4, 5 };int sz = sizeof(arr) / sizeof(arr[0]);Vector<int> s1(arr, sz);s1.Display();s1.PushBack(1);s1.PushBack(1);s1.PushBack(1);s1.PushBack(1);s1.Display();s1.PushBack(7);//尾插s1.Display();s1.PopBack();//尾删s1.PopBack();s1.Display();s1.Insert(2, 9);//指定位置插入s1.Display();s1.Erase(2);//指定位置删除s1.Display();s1.Resize(6, 10);s1.Display();s1.Resize(4);s1.Display();s1.Resize(10);s1.Display();s1.clear();s1.Display();system("pause");return 0;}