(Pre- and Post- Order Correspondence, Suppose that for a graph G you are given the list of the pre-order numbers of its n vertices and the list of the post-order numbers of its n vertices. Show that...

(Pre- and Post- Order Correspondence, Suppose that for a graph G you are given the list of the pre-order numbers of its n vertices and the list of the post-order numbers of its n vertices. Show that it is possible to determine which pre-order numbers correspond to which post-order numbers (in terms of being the pre- and post-order numbers for the same vertex).