title: Implementing Pigeonhole Sort in Java
body: <p>What is the simplest implementation of <em>Pigeonhole</em> Sort in Java? An array of array-lists is ideal, but Java makes this difficult if one wants to remain type-safe. Both an array of arrays or an array-list of array-lists can be used, but are somewhat awkward. I was wondering if there was a general recommendation for what data structure is best.</p>