ISSN:
1432-0541
Keywords:
Huffman trees
;
Near optimal trees
;
Optimal trees
;
Parallel algorithms
;
PRAM
;
Prefix codes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Computer Science
,
Mathematics
Notes:
Abstract We present parallel algorithms to construct binary trees with almost optimal weighted path length. Specifically, assuming that weights are normalized (to sum up to one) and error refers to the (absolute) difference between the weighted path length of a given tree and the optimal tree with the same weights, we present anO (logn)-time andn(log lognl logn)-EREW-processor algorithm which constructs a tree with error less than 0.18, andO (k logn log* n)-time andn-CREW-processor algorithm which produces a tree with error at most l/n k , and anO (k 2 logn)-time andn 2-CREW-processor algorithm which produces a tree with error at most l/n k . As well, we describe two sequential algorithms, anO(kn)-time algorithm which produces a tree with error at most l/n k , and anO(kn)-time algorithm which produces a tree with error at most $$1/2^{n2^k }$$ . The last two algorithms use different computation models.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01941687
Permalink