Irish dance (typically the top half of dancers graded after the first two rounds) of dancers are invited back to perform. The Céilí dances used in competitions are more precise versions of those danced in less formal settings. There is a list of 30 Céilí dances which have been standardised and published in An Coimisiún's "Ar Rinncidhe Foirne" as examples of typical Irish folk dances; these are called the "book" dances by competitive stepdancers. Most Irish dancing competitions only ask for a short piece of any given dance, in the interests of time. There are two types of shoes; soft shoes (also
Activity selection problem that |S'| > |S| in the case that multiple maximal solutions have equal sizes. The activity selection problem is notable in that using a greedy algorithm to find a solution will always result in an optimal solution. A pseudocode sketch of the iterative version of the algorithm and a proof of the optimality of its result are included below. Line 1: This algorithm is called "Greedy-Iterative-Activity-Selector", because it is first of all a greedy algorithm, and then it is iterative. There's also a recursive version of this greedy algorithm. Note that these arrays are indexed starting from 1 up to