使用“virtual … =0”的方式去声明纯虚函数，而在结尾加上对应的const，则表明该成员函数并不能够对类的成员进行修改
对于大型的数据量，要尽量调用的引用来进行传值，减少内存消耗
如果不需要修改形参的值，可在形参前面加上const，声明为的常量
LinerList.h文件
#ifndef _LINERLIST_H #define _LINERLIST_H #include "AbstractList.h" #include <iostream> using namespace std; template <class T> class LinerList:public AbstractList<T> { public: LinerList(int maxSize=10); ~LinerList(){delete []element;} bool isEmpty()const{return length==0;}; int getLength()const {return length;}; bool findElement(int k,T& x)const; //find the element whose index is k and assign the result to the x int searchElement(const T& x)const; //search the x element and return its index AbstractList<T>& Delete(int k,T& x); //delete the x element ,return the deleted Linklist and return the deleted element AbstractList<T>& insert(int k,const T& x); //insert the element at the position whose index is k void output() const; AbstractList<T>& add(const T& x); private: int length; int maxSize; T* element; }; template <class T> LinerList<T>::LinerList(int maxSize) { element = new T[maxSize]; this->maxSize = maxSize; length = 0; } //find the element whose index is k and assign the result to the x template <class T> bool LinerList<T>::findElement(int k,T& x)const { if(k<0 || k>length) { cout<<"error:out of index!"<<endl; return false; //the result of the function is the type of bool } //the index of array is from zero! x = element[k-1]; return true; //the reference cannot be changed! //the meaning of the = is copy not change the reference! } //search the x element and return its index template<class T> int LinerList<T>::searchElement(const T& x)const { if(isEmpty()) return -1; //for the illegal value use illegal value to represent for! for(int i = 0;i < length;i++) { if(element[i] == x) { return ++i; //caution:the index of the LinerList is one more than array! } } return -1; } //delete the x element ,return the deleted Linklist and return the deleted element template<class T> AbstractList<T>& LinerList<T>::Delete(int k,T& x) { if(findElement(k,x)) { for(int i = k; i < length; i ++) { element[i-1] = element[i]; } length --; return *this; } else { cout<<"out of the index"<<endl; return *this; } //almost forget it } //insert the element at the position whose index is k template<class T> AbstractList<T>& LinerList<T>::insert(int k,const T& x) { if(!(length == 0 && k == 1)) { if(k>length || k<1) { cout<<"out of the index!"<<endl; return *this; } int i = 0; //move and copy the revelant element for(i = length - 1; i >= k-1 && i >= 0; i --) { element[i + 1] = element[i]; } //insert the element in the targeted position } element[k - 1] = x; length ++; return *this; } template <class T> void LinerList<T>::output() const { cout<<"the length of the LinerList is:"<<length<<endl; cout<<"List is:"; for(int i = 0;i < length;i ++) { cout<<element[i]<<" "; } cout<<endl; } template <class T> AbstractList<T>& LinerList<T>::add(const T& x) { if(length == maxSize) { cout<<"out of memeory!add the element absortively"<<endl; return *this; } element[length] = x; length ++; return *this; } #endif // _LINERLIST_H main测试文件 #include <iostream> #include "LinerList.h" using namespace std; int main() { LinerList<int> L(5); cout<<"length:"<<L.getLength()<<endl; cout<<"is empty:"<<L.isEmpty()<<endl; L.add(1).add(2).add(3).add(4); L.output(); L.insert(1,8).insert(1,88); L.output(); int z; L.findElement(1,z); cout<<"the found element is:"<<z<<endl; L.Delete(3,z); cout<<"the deleted element is : "<<z<<endl; return 0; }
