/*自家的*/
List Reverse( List L){
    if(L == NULL) return L;
    List pre = NULL, nex = L->Next, head = L;
    while(L != NULL){
        pre = L;
        L = nex;
        if(L != NULL) {
            nex = L->Next;
            L->Next = pre;
        }
        else {
            head->Next = NULL;
            head = pre;
        }
    }
    return head;
}

/*别人家的*/
List Reverse(List head)
{
    if(NULL==head|| NULL==head->Next)
        return head;
    List p;
    List q;
    List r;
    p = head;
    q = head->Next;
    head->Next = NULL;
    while(q){
        r = q->Next;
        q->Next = p;
        p = q;
        q = r;
    }
    head=p;
    return head;
}