C# Coding Test Course, Bubble Sort

In this course, we will explore Bubble Sort, which is one of the algorithms frequently tested in C# coding tests. Bubble sort is the simplest and easiest-to-understand sorting algorithm among all sorting algorithms. In this course, we will cover the concept of bubble sort, its implementation method, and problems you may encounter in actual job coding tests.

Overview of Bubble Sort

Bubble sort is a simple sorting algorithm that sorts by comparing two adjacent elements. The name ‘bubble’ comes from the fact that the largest element ‘bubbles’ to the end of the array during this process. The basic flow of the algorithm is as follows:

1. Iterate from the beginning to the end of the array.
2. Compare each adjacent pair of elements and swap their positions if the former is greater than the latter.
3. Repeat steps 1 and 2 until you reach the end of the array.
4. Repeat the process until each element finds its correct position. Continue until the entire array is sorted.

Time Complexity of Bubble Sort Algorithm

The average time complexity of bubble sort is O(n²). This happens because, when the length of the array is n, the algorithm repeats the process n-1 times, performing n-1 comparisons during each inner iteration. However, in the best case (when the array is already sorted), it has a time complexity of O(n).

Advantages and Disadvantages of Bubble Sort

Advantages

• Simple and intuitive implementation.
• Uses less memory and is a stable sort.

Disadvantages

• Sorting performance is poor, making it inefficient for large data sets or complex sorting needs.
• Compared to other efficient sorting algorithms, its performance is lower.

Solution

We will sort the given array in ascending order using bubble sort. Below is the solution for the problem.

C#
using System;

class Program
{
    static void Main(string[] args)
    {
        int[] array = { 64, 34, 25, 12, 22, 11, 90 };
        BubbleSort(array);
        
        Console.WriteLine("Sorted Array: " + string.Join(", ", array));
    }

    static void BubbleSort(int[] arr)
    {
        int n = arr.Length;
        for (int i = 0; i < n - 1; i++)
        {
            for (int j = 0; j < n - i - 1; j++)
            {
                if (arr[j] > arr[j + 1])
                {
                    // Swap arr[j] and arr[j+1]
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        }
    }
}

Code Explanation

This code uses a function called BubbleSort to sort the array. The BubbleSort function works as follows:

1. Get the size of the array.
2. Use two nested loops to iterate through the array.
3. The first loop generally finds the maximum value for each element, while the second loop handles the comparison and swapping of adjacent elements.
4. Once sorting is complete, print the result.

Conclusion

The bubble sort algorithm is a fundamental sorting method that is particularly useful for beginners, helping to understand algorithms. Through this course, aim to enhance your understanding of bubble sort and prepare to solve basic problems in coding tests. Additionally, it would be beneficial to learn about efficient sorting algorithms as well.