Question

我有一位理论家,其钥匙是Excel平地物体(无,不流通),定义如下(电池组是一种含有各种细胞特性的物体):

Dim dic As New Dictionary(Of Excel.Range, CellProp)(New RangeComparer())

由于钥匙是物体,我需要超负荷行使平等/平等职能。我目前的执行情况如下:

Class RangeComparer
Implements IEqualityComparer(Of Excel.Range)
Public Overloads Function Equals(ByVal x As Excel.Range, ByVal y As Excel.Range) As Boolean Implements IEqualityComparer(Of Excel.Range).Equals
    If x.Address(External:=True) = y.Address(External:=True) Then
        Return True
    Else
        Return False
    End If
End Function
Public Overloads Function GetHashCode(ByVal obj As Excel.Range) As Integer Implements IEqualityComparer(Of Excel.Range).GetHashCode
      Return obj.Count.GetHashCode
    End Function
End Class

However, this can be pretty slow to execute when adding many cells (i.e. hundreds) to the Dictionary at once. Most importantly, is there a faster way to do this? Secondarily, why does getting the hash code for the Range s Count property seem to work (albeit slowly)?

Answer 1

您不妨对略作研究。编制人员对哈希语的编码是任意的,可加以确定。唯一一件事是,如果2例不相同,那么其散射代码应当有所不同。如果你收集了几乎全部散列代码相同的藏书(即算法=1),那么你的字典仍然只做罚款,但被降级为线性搜索,这非常低效。这是因为几乎所有的事例都产生散射碰撞,因此,洗衣不会带来好处。

例如,你可以尝试的另一个散列代码算法是从囚室名称中生成的,这些囚室的碰撞应当大大减少:

Public Overloads Function GetHashCode(ByVal obj As Excel.Range) _ As Integer Implements IEqualityComparer(Of Excel.Range).GetHashCode Return obj.Address(External:=True).GetHashCode End Function

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