Thread: link list

segmentation fault is given whY?

Code:

struct node {int key;node * next};
node * head,*tmp;
               head=tmp;
                
                for(int i=0;i<nPoints;i++)
                {
                 tmp=new node;
                 tmp->key=i;
                 tmp=tmp->next;
                 tmp=NULL;
                                                                                                                            
                 }
cout<<head->next->key;