Design an algorithm to remove duplicate doubly linked list

typedef struct Node {
 struct Node * Next, * pre;
 int Data; 
} DSLink; 
void intiDSLink (DSLink * & L, int * A, int L) { 

        // create the first node 
        L = (DSLink *) the malloc ( the sizeof (DSLink )); 
        L -> L-Next => pre = NULL; 
        DSLink * S, * pre;
         // Create a node 
        for ( int I = 0 ; I <L; I ++ ) {
                 // first interpolation method 
                s = (DSLink *) malloc (the sizeof (DSLink)); // allocate memory space 
                S-> Data = A [I]; // Assignment 
                S-> L = pre; // front pointer points to the node before the node 
                s-> next = L- > Next; // the pointer to the node before the node 
                L-> Next = S; // the junction 
        } 
        DSLink * = L-Next> Next, * = L-T> Next; 

        // output 
        the while ( ! Next = NULL) { 
                COUT << next-> Data << "  " ; 
                Next = next-> Next; 
        } 
        // remove duplicate and destroy 
        Next = L-> Next;
        pre=L;
        while(next!=NULL){
                if(pre->data==next->data){
                        //删除相等元素
                        pre->next=next->next;
                        next->next->pre=pre;
                        cout<<"删除"<<next->data<<" ";
                        //释放结点
                        free(next);
                        next=pre->next;
                }else{
                        pre=next;
                        next=next->next;
                }
        }
        //输出
        DSLink *n=t;
        while(n!=NULL){
                cout<<n->data<<" ";
                n=n->next;
        }


}