C# program to selection Sort with demo code

 using System;  
 using System.Collections.Generic;  
 using System.Linq;  
 using System.Text;  
 using System.Threading.Tasks;  
 using System.Diagnostics;  
 namespace sorting  
 {  
   class Sorting10  
   {  
     public static void SelectionSort<T>(T[] arr) where T : IComparable<T>  
     {  
       Debug.Assert(arr != null, "Array is null!");  
       for (int index = 0; index < arr.Length - 1; index++)  
       {  
         int minElementIndex = FindMinElementIndex(arr, index, arr.Length - 1);  
         Swap(ref arr[index], ref arr[minElementIndex]);  
       }  
       for (int i = 0; i < arr.Length - 1; i++)  
       {  
         Debug.Assert(arr[i].CompareTo(arr[i + 1]) < 0, "The array isn't sorted!");  
       }  
     }  
     public static int BinarySearch<T>(T[] arr, T value) where T : IComparable<T>  
     {  
       Debug.Assert(arr != null, "Array is null");  
       Debug.Assert(value != null, "Searched value cannot be null!");  
       for (int i = 0; i < arr.Length - 1; i++)  
       {  
         Debug.Assert(arr[i].CompareTo(arr[i + 1]) <= 0, "The array is not sorted!");  
       }  
       int index = BinarySearch(arr, value, 0, arr.Length - 1);  
       return index;  
     }  
     private static int FindMinElementIndex<T>(T[] arr, int startIndex, int endIndex)  
       where T : IComparable<T>  
     {  
       Debug.Assert(arr != null, "Array is null!");  
       Debug.Assert(startIndex >= 0, "Start index cannot be negative!");  
       Debug.Assert(endIndex >= 0, "End index cannot be negative!");  
       Debug.Assert(endIndex <= arr.Length - 1, "End index should be smaller than the length of the array!");  
       Debug.Assert(startIndex <= endIndex, "Start index should be smaller than or equal to the end index!");  
       int minElementIndex = startIndex;  
       for (int i = startIndex + 1; i <= endIndex; i++)  
       {  
         if (arr[i].CompareTo(arr[minElementIndex]) < 0)  
         {  
           minElementIndex = i;  
         }  
       }  
       // verifies if the found element is the smallest one  
       for (int i = startIndex; i <= endIndex; i++)  
       {  
         Debug.Assert(arr[minElementIndex].CompareTo(arr[i]) <= 0, "Element with value" + arr[minElementIndex] + " is not the smallest in the given array!");  
       }  
       return minElementIndex;  
     }  
     private static void Swap<T>(ref T x, ref T y)  
     {  
       T oldX = x;  
       x = y;  
       y = oldX;  
     }  
     private static int BinarySearch<T>(T[] arr, T value, int startIndex, int endIndex)  
       where T : IComparable<T>  
     {  
       Debug.Assert(startIndex <= endIndex, "Start index should be smaller than or equal to end index!");  
       Debug.Assert(startIndex >= 0, "Start index cannot be negative!");  
       Debug.Assert(endIndex >= 0, "End index cannot be negative!");  
       Debug.Assert(endIndex <= arr.Length - 1, "End index should be smaller than the length of the array!");  
       while (startIndex <= endIndex)  
       {  
         int midIndex = (startIndex + endIndex) / 2;  
         if (arr[midIndex].Equals(value))  
         {  
           return midIndex;  
         }  
         if (arr[midIndex].CompareTo(value) < 0)  
         {  
           // Search on the right half  
           startIndex = midIndex + 1;  
         }  
         else  
         {  
           // Search on the right half  
           endIndex = midIndex - 1;  
         }  
       }  
       // Searched value not found  
       return -1;  
     }  
     public static void Main()  
     {  
       int[] arr = new int[] { 3, -1, 15, 4, 17, 2, 33, 0 };  
       Console.WriteLine("arr = [{0}]", string.Join(", ", arr));  
       SelectionSort(arr);  
       Console.WriteLine("sorted = [{0}]", string.Join(", ", arr));  
       SelectionSort(new int[0]); // Test sorting empty array  
       SelectionSort(new int[1]); // Test sorting single element array  
       Console.WriteLine(BinarySearch(arr, -1000));  
       Console.WriteLine(BinarySearch(arr, 0));  
       Console.WriteLine(BinarySearch(arr, 17));  
       Console.WriteLine(BinarySearch(arr, 10));  
       Console.WriteLine(BinarySearch(arr, 1000));  
     }  
   }  
 }