计算同一时期发生的时间的算法

我已经为这个问题制定了一个算法，但仍然遇到了麻烦。

假设我有日程安排的回顾（包含名为 GV 的 gridview）：

TimeStart  TimeEnd   TotalOccuredOnThisTime
----------------------------------------------
08.00      08.50     1
08.00      09.40     43
08.00      10.50     2

Pls take a look to the picture below for more clear information:

我想从算法中得到的是，计算同一时期内发生的时间，例如在 08:00 的时间，发生了 46 个事件（参见黄色行）。

这是我的算法：

Dim ColumnLength As Integer = GV.Rows.Count
Dim TimeStart(ColumnLength - 1) As Integer
Dim TimeEnd(ColumnLength - 1) As Integer
Dim Total(ColumnLength - 1) As Integer

For i = 0 to ColumnLength - 1
  TimeStart(i) = Convert.ToInt32(Regex.Replace(GV.Rows(i).Cells(0).Text, ".", ""))
  TimeEnd(i) = Convert.ToInt32(Regex.Replace(GV.Rows(i).Cells(1).Text, ".", ""))
  Total(i) = 0
Next 

For i = 0 To ColumnLength - 2
  For j = 0 To ColumnLength - 1        
    If TimeEnd(i) > TimeStart(j) And ((TimeStart(i) <= TimeEnd(j)) Or (TimeStart(i) >= TimeEnd(j))) 
      Total(j) = Total(j) - Total(i)
    End If
  Next
Next

但这导致了错误的值。

我想要的结果是这样的：

Time: 08.00 - 08.50   --> 46 event occured
      08.50 - 09.40   --> 46 event occured
      09.40 - 10.00   --> 45 event occured
      etc...

如何正确地做到这一点？真的需要你的帮助...

您可以使用Dictionary http://msdn.microsoft.com/en-us/library/x525za90.aspx#Y456通过将两个时间字符串连接在一起来跟踪时间范围Key（不需要转换为整数），然后对于该范围的每次出现，您可以增加Value的一部分Dictionary.

此外，使用此方法不需要嵌套循环，也不需要分段循环来填充开始和结束时间数组。以下算法应该提供您正在寻找的结果：

Dim columnLength As Integer = GV.Rows.Count
Dim timeRangeCount As New Dictionary(Of String, Integer)

For i = 0 to columnLength - 1
  Dim timeStart As String = GV.Rows(i).Cells(0).Text
  Dim timeEnd As String = GV.Rows(i).Cells(1).Text
  Dim key As String = String.Format("{0}-{1}", timeStart, timeEnd)

  If timeRangeCount.ContainsKey(key)
      timeRangeCount(key) += 1
  Else
      timeRangeCount(key) = 1
  End If
Next

因此，您可以从字典中提取时间范围 09.40 - 10.00 的计数，方法是：

Dim totalOccuredOnThisTime As Integer = timeRangeCount("09.40-10.00")

I've verified该算法具有类似的测试代码：

Dim columnLength As Integer = 6
Dim timeStart() As String = {"08.00", "08.00", "10.00", "08.00", "08.00", "10.00"}
Dim timeEnd() As String = {"08.50", "08.50", "11.00", "09.00", "08.50", "11.00"}
Dim timeRangeCount As New Dictionary(Of String, Integer)

For i = 0 to columnLength - 1
  Dim key As String = String.Format("{0}-{1}", timeStart(i), timeEnd(i))

  If timeRangeCount.ContainsKey(key)
      timeRangeCount(key) += 1
  Else
      timeRangeCount(key) = 1
  End If
Next

Console.WriteLine(timeRangeCount)

Update

阅读评论中的说明后，您仍然可以使用字典以及几个帮助器类来帮助跟踪这一点（TimeRange, TimeRangeCounter, and TimeRangeEqualityComparer）。但这确实让事情变得更加复杂。

第一个帮助器类用于保存精确匹配和子范围匹配的计数：

Public Class TimeRangeCounter
    Property ExactRangeMatch as Integer
    Property SubRangeMatch as Integer
End Class

第二个辅助类用于帮助字典了解一个键（类型为TimeRange) 与另一个不同：

Public Class TimeRangeEqualityComparer 
    Implements IEqualityComparer(Of TimeRange)

    Public Overloads Function Equals(left As TimeRange, right As TimeRange) _
            As Boolean Implements IEqualityComparer(Of TimeRange).Equals           

        Return left.ToString = right.ToString   
    End Function

    Public Overloads Function GetHashCode(range As TimeRange) _
            As Integer Implements IEqualityComparer(Of TimeRange).GetHashCode

        return range.ToString().GetHashCode()
    End Function

End Class

第三个辅助类存储范围的开始和结束时间：

Public Class TimeRange 
    Private readonly _start
    Private readonly _end

    Public Readonly Property Start 
        Get
           return _start
        End Get
    End Property

    Public Readonly Property [End] 
        Get
           return _end
        End Get
    End Property

    Public Sub New(start As String, [end] As string)
        Me._start = start
        Me._end = [end]
    End Sub

    Public Overrides Function ToString() as String
       Return String.Format("{0}-{1}", Start, [End])
    End Function

End Class

因此，使用上面的内容我们应该能够编写这个算法：

Dim columnLength As Integer = 5
Dim timeStart() As String = {"08.00", "08.00", "10.00", "08.00", "08.00"}
Dim timeEnd() As String = {"08.50", "11.50", "11.00", "09.00", "08.50"}
Dim comparer As New TimeRangeEqualityComparer()
Dim timeRangeCounts As New Dictionary(Of TimeRange, TimeRangeCounter)(comparer)

'Count exact range matches while building dictionary
For i = 0 to columnLength - 1
  Dim key As TimeRange = New TimeRange(timeStart(i), timeEnd(i))

  If timeRangeCounts.ContainsKey(key)
      timeRangeCounts(key).ExactRangeMatch += 1
  Else
      Dim counter =  New TimeRangeCounter()
      counter.ExactRangeMatch = 1
      timeRangeCounts(key) = counter
  End If        

Next           

'Count sub ranges          
For Each kvp in timeRangeCounts
    For Each key in timeRangeCounts.Keys
        If kvp.key.Start >= key.Start AndAlso _ 
           kvp.Key.End <= key.End AndAlso _
           kvp.key.ToString <> key.ToString then           

            kvp.Value.SubRangeMatch += 1
        End If
    Next
Next

Console.WriteLine(timeRangeCounts)