> Where, in any of my day-to-day job duties, ... Off the top of my head, or at least where I've used them recently: > kth permutation of a set of numbers? Pr

> Where, in any of my day-to-day job duties, ... Off the top of my head, or at least where I've used them recently: > kth permutation of a set of numbers? Producing all pairs of a collection, e.g. for computing the minimum distance between elements (via map/reduce). > clone a directed graph Any object in an OO language (like JavaScript) is essentially a directed graph, so, cloning one of those.