Some results on Hu's conjecture concerning binary trees
نویسنده
چکیده
Given n weights, w I, w2, . . . , w,, such that 0 G w 1 G w2 S. . . s w ,, we examine a property of permutation #, where 7~* = (w,, w,,, w2, w,,_r, . . .), concerning alphabetical binary trees. For each permutation ‘CT of these n weights, there is an optimal alphabetical binary tree corresponding to ‘TT, we denote it’s cost by V(m). There is also an optimal almost uniform alphabetical binary tree, corresponding to W, we denote it’s cost by VU(*). This paper asserts that V,(n*) > V,,(m) > V(T) for all 7~. This is a preliminary result concerning the conjecture of T.C. Hu. Hu’s conjecture is V(n*)a V(m) for all P.
منابع مشابه
Wiener Indices of Binary Trees
One of the most widely known topological index is the Wiener index. The Wiener Index Conjecture states that all positive integer numbers except a finite set are the Wiener indices of some trees. We explore the Wiener indices of the binary trees. We present efficient algorithms for generating the Wiener indices of the binary trees. Based on experiments we strengthen the conjecture for the class ...
متن کاملOn Embedding Binary Trees into Hypercubes
Hypercubes are known to be able to simulate other structures such as grids and binary trees. It has been shown that an arbitrary binary tree can be embedded into a hypercube with constant expansion and constant dilation. This paper presents a simple linear-time heuristic which embeds an arbitrary binary tree into a hypercube with expansion 1 and average dilation no more than 2. We also give som...
متن کاملNon-hereditary Maximum Parsimony trees.
In this paper, we investigate a conjecture by Arndt von Haeseler concerning the Maximum Parsimony method for phylogenetic estimation, which was published by the Newton Institute in Cambridge on a list of open phylogenetic problems in 2007. This conjecture deals with the question whether Maximum Parsimony trees are hereditary. The conjecture suggests that a Maximum Parsimony tree for a particula...
متن کاملLower bounds on the rotation distance of binary trees
The rotation distance d(S, T ) between two binary trees S, T of n vertices is the minimum number of rotations to transform S into T . While it is known that d(S, T ) ≤ 2n− 6, a well known conjecture states that there are trees for which this bound is sharp for any value of n ≥ 11. We are unable to prove the conjecture, but we give here some simple criteria for lower bound evaluation, leading fo...
متن کاملA New Heuristic Algorithm for Drawing Binary Trees within Arbitrary Polygons Based on Center of Gravity
Graphs have enormous usage in software engineering, network and electrical engineering. In fact graphs drawing is a geometrically representation of information. Among graphs, trees are concentrated because of their ability in hierarchical extension as well as processing VLSI circuit. Many algorithms have been proposed for drawing binary trees within polygons. However these algorithms generate b...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete Mathematics
دوره 29 شماره
صفحات -
تاریخ انتشار 1980