my list error!!

[wbgxx]

#include<iostream>
using namespace std;
class list
{
public:
    int number,score;
    char name[10];
    class list*next;
};
 
void create(list* head)
{
    list* p=head;
    while(1)
    {
        list* pp=new node;
        if(!pp)
        {
            cout<<"erroe"<<endl;
            exit(1);
        }
        cout<<"Please input the student ID：";
        cin>>pp->number;
        if(pp->number==0)
            break;
        else
        {
 
            cout<<"Pleast input the studnet name";
            cin>>pp->name;
            cout<<"Please input score：";
            cin>>pp->score;
            p->next=pp;
            p=pp;
        }
 
    }
}
 
void show(list* head)
{
    list* ptr=head;
    cout<<"\n --  STUDNET  ---"<<endl;
    cout<<"ID\tNAME\tscore\n============================"<<endl;
    while(ptr!=NULL)
    {
        cout<<ptr->number<<"\t"<<ptr->name<<"\t"<<ptr->score<<endl;
        ptr=ptr->next;
 
    }
}
 
int main()
{
    list* head=NULL;
    create(head);
    show(head);
    return 0;
}

[wbgxx]

there is a error in runtime

[weaknessforcats]

It looks like head in NULL in main() after the return from create. Then you use the null pointer with the -> operator in show and die right there.

You need to pass the address of head to create. The argument to create should be list** so you can put the address of the created node into head by using *head = new node in create.

Do you have a debugger you can use? Usually you can step through code and see exactly where it fails.

[johny10151981]

In line 56 you have called create function with variable head which is null

In line 13 you have assigned
p = head
which mean p is null;
but in line 33 you did
p->next=pp;
but still p is null. You cant do that. Try allocate some memory.

But you should also check your logic. Cause in line 34 you did
p=pp;

So re-think what do want to do...
I think your logic will be something like that... First before line 56 allocate some memory for head(use malloc).

in the function do something like that (or better you think)
while()
{
...
some logic to control loop.
...
pp = new ...();
p->next=pp;
p->...=your_data();
}while()

above logic is not complete. You better complete yourself. (I am not that good)

Best Regards,
JOHNY