Binomial heap
The binomial heap data structure implements a priority queue. Arbitrary elements are added to the heap (i.e. queue), and at any time the minimum element can be removed. Additionally, a binomial heap can move all of its elements into another heap (merging). All of these individual operations take O(log n) time, where n is the number of elements in the heap.
I first implemented this data structure in university 2nd year in a computer science algorithms course. Though there are many implementations by others published online, the reason I’m publishing mine is because searching on the web, the code I saw was messy, not generic, or possibly containing subtle bugs. I hope my code will be useful for people looking to understand the algorithm and those extending my work.
Source code
 Java (SE 5+)

The class implements the
java.util.Queue
interface, so it can be used as a dropin replacement ofPriorityQueue
as long asiterator()
is not called. The maximum queue size is unlimited, butsize()
will throw an exception aboveInteger.MAX_VALUE
.  Python (compatible with 2 and 3)

This implementation only supports the methods {
enqueue()
,dequeue()
,peek()
,merge()
,clear()
} and the builtin functionlen()
.  C++ (C++11 and above)

The class is modeled after the Java version, supporting the methods {
size()
,enqueue()
,dequeue()
,peek()
,merge()
,clear()
}. It’s similar to the features provided bystd::priority_queue
.
License: MIT (open source)