[填空題] 以下程序的功能是驗證"數(shù)學黑洞6174"。對于任意一個各位數(shù)字不全部相同的四位整數(shù),將組成該數(shù)的數(shù)字組合成一個最大的數(shù)和一個最小的數(shù),二者相減,判斷其差值是否為6174,若不是,再將相減的結(jié)果組合成新的最大的數(shù)和最小的數(shù),以上過程最多重復(fù)7次,必得結(jié)果6174。程序運行界面如圖所示。 Option Explicit Option Base 1 Private Sub Cmd1_Click()Dim i As Integer,k As IntegerDim max As Integer min As Integerk=Val(Text1)For i=1 T0 3 ’判斷4位數(shù)字是否全部一樣 If Mid(CStr(k),i,1)Mid(CStr(k),i+1,1) Then ___(26)___Next iIf i>3 Then MsgBox "輸入的數(shù)據(jù)不合要求" Text1="" Exit SubEnd IfFor i=1 To 7 Call Validate(k max,min) List1.AddItcm k &":" & max &"-" & min & "=" & max-min If max-min=6174 Then Exit For Else k=___(27)___ End IfNext iIf ___(28)___ Then List1.AddItem "驗證失敗!" End Sub Private Sub Validate(n As Integer,max As Integer,min As Integer)Dim i As Integer,t(4)As IntegerDim s As String,s1 As String,s2 As StringS=CStr(n)For i=1 To 4 t(i)=Val(Mid(s,i,1))Next iCall sort(t)For i=1 To 4 s1=s1 & CStr(t(i)) s2=___(29)

Exit forMax-mini>7 或 i=8Cstr(t(i)) & s2A(i)> a(j)