求助,为什么没有输出啊??

#include
using namespace std;
class list

{

public:
list* head;
list* tail;
list* next;
list* t;
int x;
list()
{

    head=tail=NULL;
}

};

class set:public list

{

private:
int size;//元素个数
public:
void get()

{   

    t=new list;
    cin>>t->x;
    t->next=NULL;
    while(t->next!=0)
    {
        tail->next=t;
        tail=t;
        t=new list;
        cin>>t->x;
        t->x=NULL;

    }

}

set(int size):list()

{

    this->size=size;

}

void search(int m)

{
    for(int i=0;i<size;i++)

    {

        if(t->x==m)

        {

            cout<<"查找到第"<<i+1<<"位"<<endl; 

        }

        t=t->next;

    }

}

void add(int m)

{

    t=new list;
    t=head;
    size++;
    while(t)
    {
        tail->next->x=m;
    }
}
void del(int m)
{
    list *x=new list;
    t=new list;
    t=head;
    while(t->next!=NULL)
    {
        if(t->next->x==m)
        {
            t->next=t->next->next;
        }
        else 
        t=t->next; 
    }
}   
void show()
{
    t=head;
    while(t!=NULL)
    {
        cout<<t->x<<" ";
        t=t->next;
    }
    cout<<endl

}
};
int main()
{
list l;
set s(3);
s.get();
s.search(1);
s.show();
s.add(2);
s.del(3);

}

https://www.imooc.com/qadetail/244249