Option Explicit
Function RealEqual(A, B, Optional Epsilon As Double = 0.00000001)
RealEqual = Abs(A - B) <= Epsilon
End Function
Function ExtendRslt(CurrRslt, NewVal, Separator)
If CurrRslt = "" Then ExtendRslt = NewVal _
Else ExtendRslt = CurrRslt & Separator & NewVal
End Function
Sub recursiveMatch(ByVal MaxSoln As Integer, ByVal TargetVal, InArr(), _
ByVal HaveRandomNegatives As Boolean, _
ByVal CurrIdx As Integer, _
ByVal CurrTotal, ByVal Epsilon As Double, _
ByRef Rslt(), ByVal CurrRslt As String, ByVal Separator As String)
Dim I As Integer
For I = CurrIdx To UBound(InArr)
If RealEqual(CurrTotal + InArr(I), TargetVal, Epsilon) Then
Rslt(UBound(Rslt)) = (CurrTotal + InArr(I)) _
& Separator & Format(Now(), "hh:mm:ss") _
& Separator & ExtendRslt(CurrRslt, I, Separator)
If MaxSoln = 0 Then
If UBound(Rslt) Mod 100 = 0 Then Debug.Print "Rslt(" & UBound(Rslt) & ")=" & Rslt(UBound(Rslt))
Else
If UBound(Rslt) >= MaxSoln Then Exit Sub
End If
ReDim Preserve Rslt(UBound(Rslt) + 1)
ElseIf IIf(HaveRandomNegatives, False, CurrTotal + InArr(I) > TargetVal + Epsilon) Then
ElseIf CurrIdx < UBound(InArr) Then
recursiveMatch MaxSoln, TargetVal, InArr(), HaveRandomNegatives, _
I + 1, _
CurrTotal + InArr(I), Epsilon, Rslt(), _
ExtendRslt(CurrRslt, I, Separator), _
Separator
If MaxSoln <> 0 Then If UBound(Rslt) >= MaxSoln Then Exit Sub
Else
'we've run out of possible elements and we _
still don't have a match
End If
Next I
End Sub
Function ArrLen(Arr()) As Integer
On Error Resume Next
ArrLen = UBound(Arr) - LBound(Arr) + 1
End Function
Function checkRandomNegatives(Arr) As Boolean
Dim I As Long
I = LBound(Arr)
Do While Arr(I) < 0 And I < UBound(Arr): I = I + 1: Loop
If I = UBound(Arr) Then Exit Function
Do While Arr(I) >= 0 And I < UBound(Arr): I = I + 1: Loop
checkRandomNegatives = Arr(I) < 0
End Function
Sub startSearch()
'The selection should be a single contiguous range in a single column. _
The first cell indicates the number of solutions wanted. Specify zero for all. _
The 2nd cell is the target value. _
The rest of the cells are the values available for matching. _
The output is in the column adjacent to the one containing the input data.
If Not TypeOf Selection Is Range Then GoTo ErrXIT
If Selection.Areas.Count > 1 Or Selection.Columns.Count > 1 Then GoTo ErrXIT
If Selection.Rows.Count < 3 Then GoTo ErrXIT
Dim TargetVal, Rslt(), InArr(), StartTime As Date, MaxSoln As Integer, _
HaveRandomNegatives As Boolean
StartTime = Now()
MaxSoln = Selection.Cells(1).Value
TargetVal = Selection.Cells(2).Value
InArr = Application.WorksheetFunction.Transpose( _
Selection.Offset(2, 0).Resize(Selection.Rows.Count - 2).Value)
HaveRandomNegatives = checkRandomNegatives(InArr)
If Not HaveRandomNegatives Then
ElseIf MsgBox("At least 1 negative number is present between positive numbers" _
& vbNewLine _
& "It may take a lot longer to search for matches." & vbNewLine _
& "OK to continue else Cancel", vbOKCancel) = vbCancel Then
Exit Sub
End If
ReDim Rslt(0)
recursiveMatch MaxSoln, TargetVal, InArr, HaveRandomNegatives, _
LBound(InArr), 0, 0.00000001, _
Rslt, "", ", "
Rslt(UBound(Rslt)) = Format(Now, "hh:mm:ss")
ReDim Preserve Rslt(UBound(Rslt) + 1)
Rslt(UBound(Rslt)) = Format(StartTime, "hh:mm:ss")
Selection.Offset(0, 1).Resize(ArrLen(Rslt), 1).Value = _
Application.WorksheetFunction.Transpose(Rslt)
Exit Sub
ErrXIT:
MsgBox "Please select cells in a single column before using this macro" & vbNewLine _
& "The selection should be a single contiguous range in a single column." & vbNewLine _
& "The first cell indicates the number of solutions wanted. Specify zero for all." & vbNewLine _
& "The 2nd cell is the target value." & vbNewLine _
& "The rest of the cells are the values available for matching." & vbNewLine _
& "The output is in the column adjacent to the one containing the input data."
End Sub
