将算法从C＃转换为VB.NET失败 [英] Convert algorithm from C# to VB.NET fail

问题描述

我正在尝试将以下算法从C＃转换为VB.NET，而我拥有的VB.NET不能产生与C＃算法相同的结果，有人可以告诉我我的转换哪里出错了吗？

I'm trying to convert the following algorithm from C# to VB.NET and the VB.NET I have is not producing the same results as my C# algorithm, can someone tell me where I've gone wrong in my conversion?

public static IEnumerable<T[]> Combinations<T>(this IEnumerable<T> elements, int k)
{
    List<T[]> result = new List<T[]>();

    // single combination
    if (k == 0)
    {
        result.Add(new T[0]);
    }
    else
    {
        int current = 1;
        foreach (T element in elements)
        { 
            //combine each element with k-1 combinations of subsequent elements
            result.AddRange(elements
                .Skip(current++)
                .Combinations(k - 1)
                .Select(combination => (new T[] { element }).Concat(combination).ToArray())
                );
        }
    }
    return result;
}

这是我在VB.NET中得到的：

This is what I've got in VB.NET:

<Extension()>
Public Function Combinations(Of T)(ByRef elements As IEnumerable(Of T), ByVal k As Integer) As IEnumerable(Of T())

    Dim result As New List(Of T())()

    'single combination'
    If k = 0 Then
        result.Add(New T(-1) {})
    Else
        Dim current As Integer = 0

        For Each element As T In elements
            'combine each element with k - 1 combinations of subsequent elements'
            Dim local As T = element
            result.AddRange(elements.Skip(current = current + 1).Combinations(k - 1).Select(Function(combs) (New T() {local}).Concat(combs).ToArray()))
        Next
    End If

    Return result
End Function

出了点问题，但我不确定是什么，我猜问题出在lambda中。

Something is wrong, but I'm not sure what, I'm guessing the problem is somewhere in the lambda.

任何人都可以指出

推荐答案

使用一个代码转换器...

Use a code converter...

<System.Runtime.CompilerServices.Extension> _
Public Shared Function Combinations(Of T)(elements As IEnumerable(Of T), k As Integer) As IEnumerable(Of T())
    Dim result As New List(Of T())()

    ' single combination
    If k = 0 Then
        result.Add(New T(-1) {})
    Else
        Dim current As Integer = 1
        For Each element As T In elements
            'combine each element with k-1 combinations of subsequent elements

            result.AddRange(elements.Skip(System.Math.Max(System.Threading.Interlocked.Increment(current),current - 1)).Combinations(k - 1).[Select](Function(combination) (New T() {element}).Concat(combination).ToArray()))
        Next
    End If

    Return result
End Function

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