19. The computer-readable storage medium of claim 18 , the operations further comprising computing the shortest distance from the kth-closest seed page to the first web page, based, at least in part, on the initial distance for the kth-closest seed page.
18. The computer-readable storage medium of claim 12 , wherein: each seed page in the n seed pages has an associated predetermined weight; and each seed page has an associated initial distance derived from the predetermined weight for the seed page.