From amortized to worst case delay in enumeration algorithms
摘要
The quality of enumeration algorithms is often measured by their delay, that is, the maximum time spent between the output of two distinct solutions. If the goal is to enumerate t distinct solutions for any given t, another relevant measure is the maximum time needed to output t solutions divided by t, a notion we call the amortized delay of the algorithm, since it can be seen as the amortized complexity of enumerating t elements of the set.
In this paper, we study the relationship between these two notions of delay. We present several schemes that transform an algorithm with polynomial amortized delay, accessible only as a black box, into an algorithm with polynomial delay. We complement these results with several lower bounds and impossibility theorems in the black-box model.