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];
开发者_如何学Go 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?
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
Here's my implementation:
public static void Swap<T>(ref T a, ref T b)
{
T t = a;
a = b;
b = t;
}
public static void InsertionSort<T>(this T[] a) where T : IComparable<T>
{
a.InsertionSort(Comparer<T>.Default.Compare);
}
public static void InsertionSort<T>(this T[] a, Comparison<T> c)
{
int n = a.Length;
for (int i = 1; i < n; ++i)
for (int k = i; k > 0 && c(a[k], a[k - 1]) < 0; --k)
Swap(ref a[k], ref a[k - 1]);
}
I do some class to do this:
public static class InsertionSort<T> where T : System.IComparable<T>
{
public static void Sort(ref T[] array)
{
T[] tmp = new T[array.Length];
tmp[0] = array[0];
for (int i = 1; i < array.Length; i++)
{
int place = FindProperPlace(tmp, array[i]);
ExpandArray(ref tmp, place);
tmp[place] = array[i];
}
array = tmp;
}
private static int FindProperPlace(T[] numbersArray, T number)
{
int j;
for (j = 0; j < numbersArray.Length; j++)
{
if (number.CompareTo(numbersArray[j]) < 0)
{
break;
}
}
return j;
}
private static void ExpandArray(ref T[] tmp, int place)
{
for (int i = tmp.Length - 1; i > place; i--)
{
tmp[i] = tmp[i - 1];
}
}
}
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