rem: lists[vn->inlist].head = vn->list.next;
add: lists[(int)vn->inlist].head = vn->list.next;
context: move_vnode(vnode *vn, int list){    if (vn->list.prev)        vn->list.prev->list.next = vn->list.next;    else        lists[vn->inlist].head = vn->list.next;    if (vn->list.next)        vn->list.next->list.prev = vn->list.prev;    else        lists[vn->inlist].tail = vn->list.prev;    lists[vn->inlist].num--;    vn->inlist = list;    vn->list.next = NULL;    vn->list.prev = lists[list].tail;    if (vn->list.prev)        vn->list.prev->list.next = vn;    else        lists[list].head = vn;    lists[list].tail = vn;    lists[list].num++;}