Binary Search Made Easy

• Download source files - 33 Kb
• Download demo project - 27 Kb

Introduction

Today I will show you how to search data using the binary tree algorithm.
It may not be the fastest algorithm you've ever seen but it's so easy to use and better than using .NET's simple structures.

Code

First we need to figure out how we sort items in our tree.
It doesn't matter if the data type is a string or a number as long as we decide how to sort items.
To do so, we create a class derived from IComparer. We add a 'Compare' function which returns 0 if the first item is equal to the second one, 1 if greater and -1 if smaller.

Create the binary search object which will accept the comparer class you created before.

BinaryIndex index = new BinaryIndex( new TestComparer(), true ); 

Add several items to this object, in our case it's a number:

index.Add( 10 ); 

index.Add( 2 );

index.Add( 21 ); 

To search the tree just call the Search method which will return an ArrayList object of the results:

ArrayList results = index.Search( 4 ); 

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Remove seems supsect with 'byMemory' Richard_N 10:47 14 Dec '06   I was curious to see if the code was as sparse as the article as previously mentioned, so I took a quick look. Looking through your logic for Remove, it appears dangerous. If it is called using the "byMemory" parameter as true, which generally means that you have a tree which supports duplicate values, you might encounter a node that has the same value before you encounter the requested addressed node. You logic appears to remove the first node that is "equal" based on however the client code has implemented its compare routine. You are not guaranteed that the client will code for this type of equality. It seems like it would make it less flexible if the client HAD to code for this as opposed to you checking it in your remove code logic. It would also make the "allow duplicates" option useless. Sign In·View Thread·PermaLink where is the article? MCHANNER 6:59 14 Dec '06   You leave out nearly every detail about what your code is doing. I would have expected an introduction into the search algorithm, and why sorting is so important. Then maybe an example of creating a sorted list etc, then details about how you implemented the algorithm in c#. Currently the article tells me nothing. Sign In·View Thread·PermaLink 1.00/5 (1 vote)

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