Introduction
In this blog, I am going to explain the Bubble sort algorithm. Bubble sort is one of the most widely used sorting algorithms by the programmers worldwide. It can be applied to any collection including array, string, numbers, or characters.
Bubble sort is very frequently asked about in job interviews. So first I am going to explain the bubble sort algorithm; Then, I will be providing a C# code to execute it.
Please refer to below link for my earlier blog on Selection sort.
The algorithm
This algorithm follows the concept of iterating through the array from the first index to the last index and comparing adjacent elements and then swapping them if they appear in the wrong order. i.e. If the next element is smaller than the current element, they are swapped.
Let us understand this with the help of an example. Let us take an input array such as - 8 5 7 3 1
The sorted output for this array is - 1 3 5 7 8
Let us see the step by step execution of the Bubble sort algorithm on the input array to get the sorted output.
![Bubble sort algorithm]()
Iteration 1: - 8 5 7 3 1 → 5 8 7 3 1 → 5 7 8 3 1 → 5 7 3 8 1→ 5 7 3 1 8
Iteration 2: - 5 7 3 1 8 → 5 3 7 1 8→ 5 3 1 7 8
Iteration 3: - 5 3 1 7 8 → 3 5 1 7 8 → 3 1 5 7 8
Iteration 4: - 3 1 5 7 8 → 1 3 5 7 8
Iteration 5: - 1 3 5 7 8
Hence, we got the sorted array in iteration 5.
Time Complexity: - Since we need to iterate the entire array for every element, the average and the worst case complexity of bubble sort is O(n²).
Conclusion
In this tutorial, we learned about the Bubble sort algorithm and its implementation using C#.