The MinPQ class represents a priority queue of generic keys. It supports the usual Insert and Delete-the-minimum operations, along with methods for peeking at the minimum key, testing if the priority queue is empty, and iterating through the keys.

This implementation uses a binary heap. The Insert and Delete-the-minimum operations take logarithmic amortized time. The Min, Count, and IsEmpty operations take constant time. Construction takes time proportional to the specified capacity or the number of items used to initialize the data structure.