arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2201.01013cs.CC
收藏

确定和非确定决策树的时间和空间复杂度

Time and space complexity of deterministic and nondeterministic decision trees

Mikhail Moshkov

摘要:

本文研究任意无限二元信息系统,其中每个系统由一个称为论域的无限集合和定义在论域上的一个无限二值函数(属性)集合组成。我们考虑的概念问题的信息系统,这是由有限数量的属性和映射对应的决策,每个元组的属性值。作为解决问题的算法,我们使用确定性和非确定性决策树。作为时间复杂度和空间复杂度,我们研究了决策树的深度和节点数。在最坏的情况下,随着问题描述中属性数量的增长,(i)确定性决策树的最小深度几乎以对数或线性方式增长,(ii)非确定性决策树的最小深度从上到下由常数限制或线性增长,(iii)确定性决策树中的最小节点数量具有多项式或指数增长,以及(iv)非确定性决策树中的最小节点数具有多项式或指数增长。在此基础上,我们将无限二进制信息系统的集合划分为五类复杂性,并针对每一类复杂性研究了决策树的时空权衡问题。

英文摘要:

In this paper, we study arbitrary infinite binary information systems each of which consists of an infinite set called universe and an infinite set of two-valued functions (attributes) defined on the universe. We consider the notion of a problem over information system which is described by a finite number of attributes and a mapping corresponding a decision to each tuple of attribute values. As algorithms for problem solving, we use deterministic and nondeterministic decision trees. As time and space complexity, we study the depth and the number of nodes in the decision trees. In the worst case, with the growth of the number of attributes in the problem description, (i) the minimum depth of deterministic decision trees grows either almost as logarithm or linearly, (ii) the minimum depth of nondeterministic decision trees either is bounded from above by a constant or grows linearly, (iii) the minimum number of nodes in deterministic decision trees has either polynomial or exponential growth, and (iv) the minimum number of nodes in nondeterministic decision trees has either polynomial or exponential growth. Based on these results, we divide the set of all infinite binary information systems into five complexity classes, and study for each class issues related to time-space trade-off for decision trees.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑