On the maximum mean subtree order of trees

نویسندگان

چکیده

A subtree of a tree is any induced subgraph that again (i.e., connected). The mean order the average number vertices its subtrees. This invariant was first analyzed in 1980s by Jamison. An intriguing open question raised Jamison asks whether maximum order, given tree, always attained some caterpillar. While we do not completely resolve this conjecture, find evidence favor proving different features trees attain maximum. For example, show diameter n with must be very close to n. Moreover, equal n−2log2n+O(1). local which all subtrees containing fixed vertex, can even more precise: broom and it n−log2n+O(1).

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The Maximum-Mean Subtree

In this paper, we define the Maximum-Mean Subtree problem on trees, an equivalent reformulation of the Fractional Prize-Collecting Steiner Tree Problem on Trees. We describe an algorithm that solves the Maximum-Mean Subtree problem, and prove that our algorithm runs in O(n) time in the worst case, improving a previous O(n log n) algorithm. 1 The Maximum-Mean Subtree Problem Given a rooted tree ...

متن کامل

The Weighted Maximum-Mean Subtree and Other Bicriterion Subtree Problems

We consider problems in which we are given a rooted tree as input, and must find a subtree with the same root, optimizing some objective function of the nodes in the subtree. When this function is the sum of constant node weights, the problem is trivially solved in linear time. When the objective is the sum of weights that are linear functions of a parameter, we show how to list all optima for ...

متن کامل

On the Maximum Common Embedded Subtree Problem for Ordered Trees

The maximum common embedded subtree problem, which generalizes the minor containment problem on trees, is reduced for ordered trees to a variant of the longest common subsequence problem. While the maximum common embedded subtree problem is known to be APX-hard for unordered trees, an exact solution for ordered trees can be found in polynomial time. In this paper, the longest common balanced se...

متن کامل

Solving the Maximum Agreement SubTree and the Maximum Compatible Tree Problems on Many Bounded Degree Trees

Given a set of leaf-labeled trees with identical leaf sets, the well-known Maximum Agreement SubTree problem (MAST) consists of finding a subtree homeomorphically included in all input trees and with the largest number of leaves. Its variant called Maximum Compatible Tree (MCT) is less stringent, as it allows the input trees to be refined. Both problems are of particular interest in computation...

متن کامل

The Subtree Size Profile of Bucket Recursive Trees

Kazemi (2014) introduced a new version of bucket recursive trees as another generalization of recursive trees where buckets have variable capacities. In this paper, we get the $p$-th factorial moments of the random variable $S_{n,1}$ which counts the number of subtrees size-1 profile (leaves) and show a phase change of this random variable. These can be obtained by solving a first order partial...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: European Journal of Combinatorics

سال: 2021

ISSN: ['1095-9971', '0195-6698']

DOI: https://doi.org/10.1016/j.ejc.2021.103388