# include  
# include  
Typedef struct _node {
The int value. 
Previous struct _node *; 
Struct _node * next; 
} the Node; 
Int main (void) {
The head Node *=NULL; 
Node * tail=NULL; 
Int j=1; 
For (int number; The scanf (" % d ", & number)==1 && number!=1) {
The Last Node *=head; 
If (j==1) {
Head=(*) malloc (sizeof (Node)); 
The head -> value=https://bbs.csdn.net/topics/number; 
The head -> next=NULL; 
The head -> previous=NULL; 
j++; 
break; 
} 
The else {
for(; The Last; The Last of the Last=-> next); 
Node * p=(*) malloc (sizeof (Node)); 
Last -> next=p; 
P -> value=https://bbs.csdn.net/topics/number; 
p->next=NULL; 
P -> previous=Last; 
Tail=p; 
} 
} 
For (Node * I=head; i; I=I -> next) {
Printf (" % d \ t ", I -> value); 
} 
For (Node * k=tail; k; {k=k -> previous) 
Printf (" % d \ t, k -> value); 
} 
return 0; 
}