منابع مشابه
Optimal Alphabetic Trees
An algorithm of Knuth for finding an optimal binary tree is extended in several directions to solve related problems. The first case considered is restricting the depth of the tree by some predetermined integer K, and a Kn algorithm is given. Next, for trees of degree tr, rather than binary trees, Kn log tr and n log tr algorithms are found for the restricted and nonrestricted cases, respective...
متن کاملOptimal Alphabetic Ternary Trees
We give a new algorithm to construct optimal alphabetic ternary trees, where every internal node has at most three children. This algorithm generalizes the classic Hu-Tucker algorithm, though the overall computational complexity has yet to be determined.
متن کاملOptimum Alphabetic Binary Trees
We describe a modiication of the Hu{Tucker algorithm for constructing an optimal alphabetic tree that runs in O(n) time for several classes of inputs. These classes can be described in simple terms and can be detected in linear time. We also give simple conditions and a linear algorithm for determining, in some cases, if two adjacent nodes will be combined in the optimal alphabetic tree.
متن کاملCorrectness of Constructing Optimal Alphabetic Trees Revisited
Several new observations which lead to new correctness proofs of two known algorithms (Hu-Tucker and Garsia-Wachs) for construction of optimal alphabetic trees are presented. A generalized version of the Garsia-Wachs algorithm is given. Proof of this generalized version works in a structured and illustrative way and clari es the usually poorly-understood behavior of both the Hu-Tucker and Garsi...
متن کاملAlphabetic Minimax Trees in Linear Time
We develop a linear time algorithm algorithm for the following problem: given an ordered sequence of n real weights w1, w2, . . . , wn, construct a binary tree on n leaves labeled with those weights when read from left to right so that the maximum value of wi plus depth of the i-th leftmost leaf is minimized. This improves the previously known O(n logn) time solutions [2,11,13]. We also give a ...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1992
ISSN: 0304-3975
DOI: 10.1016/0304-3975(92)90334-c