Implementation of the prefix tree(trie) data structure in C#

Update: all the source code for this article can be accessed from here

A prefix tree is a data structure with many uses. I won't go into details about this data structure Wikipedia does a better job than I could. What I will do is post a C# implementation of this data structure and in a following post I will show how to use this data structure when implementing an auto-complete solution.

These are the properties of a prefix tree:

• it stores strings(finite sequences of chars)
• it had nodes :) (doooooooh!)
• each node stores a character
• each node can have a number of subnodes(0,1,2, ... infinity)
• the char stored in a subnode is the one following the char stored by the node in a string
• each node has a flag which is raised if a word ends there(this doesn't mean it can't have subnodes for example a prefix tree can store the words "cat" and "catastrophy" in this case node 3 stores 't' and has a subnode that stores 'a')

And now the code:

The node:



The tree:

The main program: