New project: data structures
Most of the code that I’ve written in the past few years has been closed-source, proprietary code for my employer. As such I have very little publicly available code to show other people. A few months ago I decided to start working on that by implementing some of the more interesting data structures that I’ve read about. The ultimate goal was to create a Fibonacci heap, which I’ve been meaning to do since I completed the final project for my algorithms class in college. We had to implement Dijkstra’s algorithm on the NYC subway system and a Fibonacci heap can lower the asymptotic bound on the running time.
I started with a Red-black tree as that is a pretty classic and oft-used data structure. Perhaps this endeavor was a little pointless as Red-black trees are usually the data structure used to implement the STL map. In a sense this was both the most useful (because of the frequency with which I use the map container) and the least useful (because it’s already available).
I then implemented two different heaps: a binomial heap and a Fibonacci heap. A binomial heap improves the running time of merging two heaps together (and uses this fact to implement most other operations using the merge) and a Fibonacci heap improves the running time of the decrease key operation – an operation that is frequently used in Dijkstra’s algorithm as well as many other graph algorithms.
The code isn’t as nice as I’d like (there is some debugging code left in, for example) but it was a good exercise and greatly took advantage of template meta-programming in C++.
The project page is here.