Linq最低唯一值或最低行和列值，以精確匹配或部分匹配中的值較小者為準

您好，我正在嘗試開發一個 Linq 查詢來查找同樣按行和列值排序的最低唯一值或最低值。
首先它執行最低唯一值完全匹配（唯一值）
如果沒有找到，那么它執行部分匹配（最低值然后最低行然后列）
具有最小值的輸出（唯一或未找到）。

資料表

輸出應該是表中的最后一個資料，0,2,2因為它具有最低的行并且它是一個重復的值（第 1 行和第 0 行）。

如果添加資料2,0,0（值為 0）將否決重復的值 ( 2's)。

   Structure FoundValue
        Dim Value As Short
        Dim Row As Integer
        Dim Column As Integer
    End Structure
  
   Dim UniqueValuesFound As New List(Of Short)
   Dim ValuesFoundInPath As New List(Of FoundValue)

   UniqueValuesFound.Add(0)
   UniqueValuesFound.Add(2)
   UniqueValuesFound.Add(3)

   Dim foundValue As New FoundValue
   foundValue.Value = 2
   foundValue.Row = 1
   foundValue.Column = 1
   ValuesFoundInPath.Add(foundValue)

   foundValue = New FoundValue
   foundValue.Value = 3
   foundValue.Row = 0
   foundValue.Column = 2
   ValuesFoundInPath.Add(foundValue)

   foundValue = New FoundValue
   foundValue.Value = 2
   foundValue.Row = 0
   foundValue.Column = 2
   ValuesFoundInPath.Add(foundValue)

   'foundValue = New FoundValue
   'foundValue.Value = 0
   'foundValue.Row = 2
   'foundValue.Column = 0
   'ValuesFoundInPath.Add(foundValue)

'New Attempt
    Dim alreadyFound As Boolean = False

    Dim matching = ValuesFoundInPath.Where(Function(s)
                                               Dim index As Integer = UniqueValuesFound.BinarySearch(s.Value)
                                               If alreadyFound = False AndAlso index >= 0 Then
                                                   alreadyFound = True
                                                   Return True 'UniqueValuesFound(index) 'exact match
                                               ElseIf alreadyFound = False AndAlso index < 0 Then
                                                   alreadyFound = True
                                                   Return True 's.Value
                                               Else
                                                   Return False
                                               End If
                                           End Function).OrderBy(Function(p) p.Value).ThenBy(Function(p) p.Row).ThenBy(Function(p) p.Column)

    'New Attempt
        Dim alreadyFound As Boolean = False

        Dim matching = ValuesFoundInPath.Where(Function(s)
                                                   Dim index As Integer = UniqueValuesFound.BinarySearch(s.Value)
                                                   If alreadyFound = False AndAlso index >= 0 Then
                                                       alreadyFound = True
                                                       Return True 'UniqueValuesFound(index) 'exact match
                                                   ElseIf alreadyFound = False AndAlso index < 0 Then
                                                       alreadyFound = True
                                                       Return True 's.Value
                                                   Else
                                                       Return False
                                                   End If
                                               End Function).OrderBy(Function(p) p.Value).ThenBy(Function(p) p.Row).ThenBy(Function(p) p.Column)

Look at 'New Attempt code it speaks itself, what I'm trying to do is find the first value which has a exact match in UniqueValuesFound and if it cannot find the value in UniqueValuesFound array then default to spitting out a partial match lowest value it can find. The array ValuesFoundInPath contains all the values in a random order as well as Column and Row types, which have to be sorted for partial match to find the lowest Row first.

uj5u.com熱心網友回復：

我終于解決了！，需要使用Find而不是Where問題消失了！。

答案現在需要 2 個 linq 查詢，而不是一個無法鏈接 Find

    ValuesFoundInPath = ValuesFoundInPath.OrderBy(Function(p) p.Value).ThenBy(Function(p) p.Row).ThenBy(Function(p) p.Column).ToList()

    Dim alreadyFound As Boolean = False

    Dim matching = ValuesFoundInPath.Find(Function(s)
                                              Dim index As Integer = UniqueValuesFound.BinarySearch(s.Value)
                                              If alreadyFound = False AndAlso index >= 0 Then
                                                  alreadyFound = True
                                                  Return True 'UniqueValuesFound(index) 'exact match
                                              ElseIf alreadyFound = False AndAlso index < 0 Then
                                                  alreadyFound = True
                                                  Return True 's.Value
                                              Else
                                                  Return False
                                              End If
                                          End Function)

    Dim result As New Result
    result.Answer = matching.Value
    result.CurrentRow = matching.Row
    result.CurrentColumn = matching.Column

您可能會遇到問題，因為Find(...)總是對值串列進行預排序。所以你需要使用FindIndex(...)它來避免排序問題。

    Dim matchingIndex = ValuesFoundInPath.FindIndex(Function(s)
                                                        Dim index As Integer = UniqueValuesFound.BinarySearch(s.Value)
                                                        If alreadyFound = False AndAlso index >= 0 Then
                                                            alreadyFound = True
                                                            Return True 'UniqueValuesFound(index) 'exact match
                                                        ElseIf alreadyFound = False AndAlso index < 0 Then
                                                            alreadyFound = True
                                                            Return True 's.Value
                                                        End If
                                                        Return False 'No match.
                                                    End Function)

    If matchingIndex < 0 Then MessageBox.Show("Wtf!")

    Dim result As New Result
    result.Answer = ValuesFoundInPath(matchingIndex).Value
    result.CurrentRow = ValuesFoundInPath(matchingIndex).Row
    result.CurrentColumn = ValuesFoundInPath(matchingIndex).Column

它使OrderBy(...)無用，因為Find(...)通過遞增值對串列進行預排序。

標籤：vb.net linq

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