Sorting wild pigs

Abstract: Chjara, breeder in Carg{`e}se, has n wild pigs. She would like to sort her herd by weight to better meet the demands of her buyers. Each beast has a distinct weight, alas unknown to Chjara. All she has at her disposal is a Roberval scale, which allows her to compare two pigs only at the cost of an acrobatic manoeuvre. The balance, quite old, can break at any time. Chjara therefore wants to sort his herd in a minimum of weighings, but also to have a good estimate of the result after each weighing.To help Chjara, we pose the problem of finding a good anytime sorting algorithm, in the sense of Kendall's tau distance between provisional result and perfectly sorted list, and we bring the following contributions:- We introduce Corsort, a family of anytime sorting algorithms based on estimators.- By simulation, we show that a well-configured Corsort has a near-optimal termination time, and provides better intermediate estimates than the best sorting algorithms we are aware of.