下面程序的功能是验证回文数猜想。取任一自然数，将其倒过来，并将这两个数相加，然后把这个和数倒过来，与原来的和数相加……重复这个过程有限次，必将得到一个回文数。所谓回文数指左右数字完全对称的自然数，例如：121，12321，898，111均是回文数）根据猜想,取一自然数68,经过三步运算就可得到回文数1111
Option Explicit

Private Sub Form_Click()
    Dim S As Double, D As Double, Sum As Double
    Dim Flg As Boolean
    S = InputBox("输入一个正整数")
    Do
       D = Fun(S)    
Sum =      
       Print Sum; "="; S; "+"; D
       Call Comp(Sum, Flg)
       S = Sum
    Loop Until     
    Print Sum; "是回文数"
End Sub
Private Function Fun(N As Double) As Double
    Dim Char As String, J As Double
    Dim I As Double, Slen As Double
    Char = LTrim(Str(N))
    Slen = Len(Char)
    J = 1
    For I = 1 To Slen
        Fun = Fun +                
        J = J * 10
    Next I
End Function
Private Sub Comp(N As Double, F As Boolean)
    Dim Char As String, Slen As Double, I As Double
    Char = LTrim(Str(N))
    Slen = Len(Char)
    For I = 1 To Slen
     If Mid(Char, I, 1) Mid(Char, Slen + 1 - I, 1) Then Exit Sub
    Next I
    F = True
End Sub