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Optimal Prefix-Free Codes for Unequal Letter Costs: Dynamic Programming with the Monge Property

✍ Scribed by Phil Bradford; Mordecai J. Golin; Lawrence L. Larmore; Wojciech Rytter


Publisher
Elsevier Science
Year
2002
Tongue
English
Weight
293 KB
Volume
42
Category
Article
ISSN
0196-6774

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✦ Synopsis


In this paper we discuss the problem of finding optimal prefix-free codes for unequal letter costs, a variation of the classical Huffman coding problem. Our problem consists of finding a minimal cost prefix-free code in which the encoding alphabet consists of unequal cost (length) letters, with lengths α and β. The most efficient algorithm known previously requires O n 2+max α β time to construct such a minimal-cost set of n codewords, provided α and β are integers. In this paper