December 11, 2021

Programmingempire

This article explains Selection Sort in C#. Like Bubble Sort and Insertion Sort, Selection Sort is also a simple sorting technique. Furthermore, selection sort also works by dividing the list into sorted and unsorted part. Unlike, insertion sort, selection sort finds minimum element from the unsorted list and puts it at the beginning. Further, the element at beginning goes to the position of the minimum element. Therefore, now the first element also becomes the part of sorted list. Initially, the whole list is unsorted. So, this algorithm finds the minimum from the whole list and swaps it with the element at first position. After that, the sorted list contains one element and unsorted list contains n-1 elements, where n is the total number of elements. The same process is repeated for rest of the ellements. The following example demonstrates the working of selection sort.

Working of Selection Sort

Let, our list is [9, 1, 22, 5, 18, 12]. At first, unsorted part= [9, 1, 22, 5, 18, 12] , and sorted part=[]. So, we find minimum from the whole list = 1. It results in swapping the elements 1 and 9. Now the list becomes [1, 9, 22, 5, 18, 12]. Further, find the minimum from the unsorted part. So, minimum = 5. After that swap it with the element 9. So, now we get the following list = [1, 5, 22, 9, 18, 12] . Next we get following list [1, 5, 9, 22, 18, 12]. Similarly, next iteration results in this list: [1, 5, 9, 12, 18, 22]. Although, our list is sorted now. But the last iteration also takes place.

Implementation of Selection Sort in C#

The following code shows Implementation of Selection Sort in C#. While, the inner loop finds minimum element. Also, the swap function swaps the current element with the minimum one.

using System;
namespace SelectionSort
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] myarray = { 4, 1, 9, -13, 90, 56, 81, 34, -2, -15, 60, 88 };
            Console.WriteLine("Array before sorting...");
            foreach (int x in myarray)
                Console.Write(x + "  ");
            Sort.SelectionSort(myarray);
            Console.WriteLine("\nArray after sorting...");
            foreach (int x in myarray)
                Console.Write(x + "  ");
            Console.WriteLine();
        }
    }
    class Sort
    {
        public static void SelectionSort(int[] myarray)
        {
            int min_index;
            for (int i = 0; i < myarray.Length - 1; i++)
            {
                min_index = i;
                for (int j = i + 1; j < myarray.Length; j++)
                {
                    if (myarray[j] < myarray[min_index])
                    {
                        min_index = j;
                    }
                }
                swap(ref myarray[i], ref myarray[min_index]);
            }
        }
        static void swap(ref int m, ref int n)
        {
            int t = m;
            m = n;
            n = t;
        }
    }
}

Output

**Implementation of Selection Sort in C#**

Programmingempire

Working of Selection Sort

Implementation of Selection Sort in C#

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