Fast calculation of optimal strategies for searching with non-uniform costs

Proposes an algorithm for finding a binary search tree that minimizes the worst-case cost when the access costs are non-uniform and depend on the last accessed key. For this kind of problem, which is commonly found when accessing data stored on magnetic or optical disks, we present an algorithm that finds an optimal search strategy with an expected running time of O(n²log n), under some reasonable assumptions on the cost matrix. It is worth mentioning that the best previous algorithm for this problem runs in Θ(n³) time