Solution: The Dutch National Flag Problem

using System;
class Program
{
    /// <summary>
    /// This method uses the selection sort approach to solve the Dutch National Flag Problem.
    /// </summary>
    /// <param name="arr">An array of integers.</param>
    /// <returns>An array with the Dutch National Flag Problem solved.</returns>
    public static int[] DutchNationalFlag(int[] arr)
    {
        int size = arr.Length;
        int index;
        for (int i = 0; i < size; i++)
        {
            index = FindMin(arr, i, size);
            Swap(arr, i, index);
        }
        return arr;
    }
    /// <summary>
    /// Finds the minimum value index in an array within a specific range.
    /// </summary>
    /// <param name="arr">An array of integers.</param>
    /// <param name="start">Starting index.</param>
    /// <param name="end">Ending index.</param>
    /// <returns>The index of the minimum value within the specified range.</returns>
    public static int FindMin(int[] arr, int start, int end)
    {
        int min = arr[start];
        int index = start;
        for (int x = start; x < end; x++)
        {
            if (arr[x] < min)
            {
                min = arr[x];
                index = x;
            }
        }
        return index;
    }
    // Swaps numbers in an array
    public static void Swap(int[] arr, int i, int j)
    {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
    // Driver to test above code
    public static void Main()
    {
        int[] array = { 2, 0, 0, 1, 2, 1 };
        int[] result = DutchNationalFlag(array);
        Console.WriteLine("[" + string.Join(", ", result) + "]");
    }
}