using System;

using System.Collections.Generic;

​

public static class Program

{

    public static void Main()

    {

        string[] shapeTypes = {"circle", "triangle", "square" };

        string[] shapeColor = { "red", "blue", "orange" };

        double[] shapeArea = { 20, 5, 4 };

        Sort(shapeArea, shapeTypes, shapeColor);

        Console.WriteLine($"shapeTypes: {String.Join(", ", shapeTypes)}");

        Console.WriteLine($"shapeColor: {String.Join(", ", shapeColor)}");

        Console.WriteLine($"shapeArea: {String.Join(", ", shapeArea)}");

    }

​

    /// <summary>

    /// Sorts three arrays, one contains the keys and the others contain

    /// the corresponding items, based on the keys in the first array.

    /// </summary>

    public static void Sort<TKey, T1, T2>(TKey[] keys, T1[] items1, T2[] items2,

        IComparer<TKey> comparer = default)

    {

        ArgumentNullException.ThrowIfNull(keys);

        ArgumentNullException.ThrowIfNull(items1);

        ArgumentNullException.ThrowIfNull(items2);

        if (items1.Length < keys.Length)

            throw new ArgumentException("Array too small.", nameof(items1));

        if (items2.Length < keys.Length)

            throw new ArgumentException("Array too small.", nameof(items2));

        comparer ??= Comparer<TKey>.Default;

​

        // Create an array of incremental indices (zero based).

        int[] indices = new int[keys.Length];

        for (int i = 0; i < indices.Length; i++) indices[i] = i;

​

        // Sort the indices according to the keys.

        Array.Sort<int>(indices, (x, y) => comparer.Compare(keys[x], keys[y]));

​

        // Sort all the arrays according to the indices.

        for (int i = 0; i < indices.Length - 1; i++)

        {

            int k = indices[i];

            while (k < i) k = indices[k];

            if (k == i) continue;

            // Swap the items in the positions i and k.

            Swap(keys, i, k);

            Swap(items1, i, k);

            Swap(items2, i, k);

        }

​

        static void Swap<T>(T[] array, int x, int y)

        {

            T temp = array[x];

            array[x] = array[y];

            array[y] = temp;

        }

    }

}

​