Minimizing access pointers into trees and arrays

摘要

Multihead tree machines and multihead multidimensional machines are used to develop new methods for minimizing access pointers into trees and arrays. Every multihead tree machine of time complexity t(n) can be simulated on-line by a tree machine with only two access heads in time O(t(n) log t(n)log log t(n)). Every multihead e-dimensional machine of time complexity t(n) can be simulated on-line by a d-dimensional machine with two access heads in time O(t(n)1 + 1d − 1de log t(n)). The simulation for trees is optimal.