Understanding Binary Search in C#

When searching data structures for specific values there are multiple methods that can be used to find a desired value. Two popular  methods are a linear search and a binary search. A linear search works by checking each item in a list or array one at a time to see if it matches the target value. This search method is best suited for unsorted data.

For example if you are given a 100 page book where all the pages are out of order and you were told to find page 45 you would use a linear search by checking each page one at a time until you find page 45. This could potentially take 100 page turns if page 45 happens to be at the end of the book of shuffled pages. With unsorted data this is necessary because each item could be in any location. However, if the data is sorted a linear search might not be the best approach. Enter binary search. 

If you are given the same 100 page book with the book pages in order as they usually are and you are told to find page 45 you would have to turn 45 pages to get to the correct page if using a linear search. In this same scenario a binary search would only have to turn 7 pages because each turn is eliminating half of the book.

When working with a sorted data structure a binary search is a much more efficient algorithm to find a specific value. Instead of starting at the beginning and looking at each item one by one a binary search works by repeatedly dividing in half the portion of the data that could contain the target value until you've narrowed down the possible location to one. Here is a step by step breakdown of a binary search followed by an example of the algorithm written in C#.

Steps to implement binary search

1. Start with a list of sorted data
2. Find the middle elment in the list
3. Compare the middle element to the target value
4. If the middle element is equal to the target value the search is complete
5. If the middle element is less than the target value repeat the search on the right side of the list
6. If the middle element is greater than the target value repeat the search on the left side  of the list
7. Continue this process until the target value is found or until there is no more data to search

The Code

In conclusion, binary search is a powerful algorithm for searching in sorted data structures. Due to it's speed it is a preferred choice for large sorted datasets. Understanding and implementing binary search in C# can signifigantly improve the performance of your application's search operations.