The following two computational problems are studied: Duplicate groupi
ng: Assume that n items are given, each of which is labeled by an inte
ger key from the set {0,...,U -1}. Store the items in an array of size
n such that items with the same key occupy a contiguous segment of th
e array.Closest pair: Assume that a multiset of n points in the d-dime
nsional Euclidean space is given, where d greater than or equal to 1 i
s a fixed integer. Each point is represented as a d-tuple of integers
in the range (0,..., U -1)(or of arbitrary real numbers). Find a close
st pair, i.e., a pair of points whose distance is minimal over all suc
h pairs.