c++实现链表的基本操作

#include<iostream>
using namespace std;
struct listnode
{
int data;
listnode* next;
};
class list
{
private:
listnode* head;
public:
list(){head=new listnode;head->next=NULL;}
~list();
void addtolist(int data);
void removenode(int data);
void print();
};
void list:: addtolist(int data)
{
listnode*p=head;
listnode*q=new listnode;
q->data=data;
q->next=NULL;


while(p->next!=NULL)
p=p->next;
p->next=q;


}
void list::removenode(int data)
{
listnode*p=head;
listnode*r=NULL;
if(p->next==NULL)
cout<<"这是空链表"<<endl;
else
{
while(p->next!=NULL&&p->next->data!=data)
p=p->next;
if(p->next!=NULL&&p->next->data==data)
r=p->next;
if(r!=NULL)
{
p->next=r->next;
delete r;
r=NULL;
}
else
cout<<"can't find!";
}


}
void list:: print()
{
listnode*p=head;
while(p->next!=NULL)
{
cout<<p->next->data<<" ";
p=p->next;
}
cout<<endl;
}
list::~list()
{
listnode*p;
while (head->next)
{
p = head;
head = head->next;
delete p;
}
delete head;
head=NULL;
p=NULL;
}
int main()
{
list list1;
list1.removenode(1);
list1.addtolist(1);
list1.addtolist(2);
list1.addtolist(3);
list1.addtolist(5);
list1.addtolist(6);
list1.addtolist(7);
list1.addtolist(8);
list1.addtolist(9);
list1.addtolist(10);
list1.print();
list1.removenode(8);
list1.print();
list1.removenode(11);
return 0;
}