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 );