sort a list via divide and conquere in csharp

main.cs
public static void MergeSort(int[] arr)
{
    if (arr.Length < 2)
        return;
 
    int mid = arr.Length / 2;
    int[] left = new int[mid];
    int[] right = new int[arr.Length - mid];
 
    for (int i = 0; i < mid; i++)
        left[i] = arr[i];
 
    for (int i = mid; i < arr.Length; i++)
        right[i - mid] = arr[i];
 
    MergeSort(left);
    MergeSort(right);
 
    Merge(arr, left, right);
}
 
public static void Merge(int[] arr, int[] left, int[] right)
{
    int i = 0, j = 0, k = 0;
 
    while (i < left.Length && j < right.Length)
    {
        if (left[i] <= right[j])
            arr[k++] = left[i++];
        else
            arr[k++] = right[j++];
    }
 
    while (i < left.Length)
        arr[k++] = left[i++];
 
    while (j < right.Length)
        arr[k++] = right[j++];
}
803 chars
40 lines

main.cs
int[] arr = { 3, 7, 4, 5, 2, 1, 6 };
MergeSort(arr);
foreach (int elem in arr)
    Console.Write(elem + " ");
110 chars
5 lines