Question

If I have an array of strings, such as

string[] names = {"John Doe", "Doe John", "Another Name", "Name Another"};

How do I sort this array, using insertion sort?

Wikipedia has some examples: https://en.wikibooks.org/wiki/Algorithm_implementation/Sorting/Insertion_sort#C.23

static void InsertSort(IComparable[] array)
{
    int i, j;

    for (i = 1; i < array.Length; i++)
    {
        IComparable value = array[i];
        j = i - 1;
        while ((j >= 0) && (array[j].CompareTo(value) > 0))
        {
            array[j + 1] = array[j];
            j--;
        }
        array[j + 1] = value;
    }
}

and

static void InsertSort<T>(IList<T> list) where T : IComparable<T>
{
    int i, j;

    for (i = 1; i < list.Count; i++)
    {
        T value = list[i];
        j = i - 1;
        while ((j >= 0) && (list[j].CompareTo(value) > 0))
        {
            list[j + 1] = list[j];
            j--;
        }
        list[j + 1] = value;
    }
}

but it doesn’t seem to work on my array of strings, unless I’m doing something wrong.

Would I not run

InsertSort(names); // like so?

Answer 1

Works fine for me:

class Program
{
    static void Main()
    {
        string[] names = { "John Doe", "Doe John", "Another Name", "Name Another" };
        InsertSort(names);
        foreach (var item in names)
        {
            Console.WriteLine(item);
        }
    }

    static void InsertSort(IComparable[] array)
    {
        int i, j;

        for (i = 1; i < array.Length; i++)
        {
            IComparable value = array[i];
            j = i - 1;
            while ((j >= 0) && (array[j].CompareTo(value) > 0))
            {
                array[j + 1] = array[j];
                j--;
            }
            array[j + 1] = value;
        }
    }
}

As expected it prints:

Another Name
Doe John
John Doe
Name Another