Private Sub Form_Click()
Dim S As String, Flg As Boolean Do
S = InputBox(\输入一个自然数\ If S = \
MsgBox \请重新输入\ Else
Exit Do End If Loop
judge(S, Flg) ' Call judge(S, Flg) 或 judge S, Flg If Flg Then
Print S; \是回文数\ Else
Print S; \不是回文数\ End If End Sub
Private Sub judge(Ch As String, F As Boolean) Dim L As Integer, I As Integer L = Len(Ch) F = True ' F = False For I = 1 To L
If Mid$(Ch, I, 1) <> Mid$(Ch, L + 1 - I, 1) Then Exit Sub Next I F = False ' F = True End Sub
四、编程题
1、编程验证任一大于2的偶数可以表示成两个素数之和。 Private Function Prime(a As Integer) As Boolean Dim i As Integer For i = 2 To Sqr(a)
If a Mod i = 0 Then Exit Function Next i
Prime = True End Function
'方法一
Private Sub Command1_Click() Dim m As Integer, i As Integer
m = InputBox(\请输入一个大于2 的偶数\
If m <= 2 Or m Mod 2 <> 0 Then MsgBox \请输入大于2的偶数\ If Prime(2) And Prime(m - 2) Then Print m & \ Else Do
i = i + 1
If Prime(2 * i + 1) And Prime(m - (2 * i + 1)) Then Print m & \ Exit Do End If
Loop While 2 * i + 1 < m - (2 * i + 1) End If End Sub '方法二
Private Sub Command2_Click()
Dim m As Integer, i As Integer, p() As Integer, n As Integer Dim flg As Boolean
m = InputBox(\请输入大于2的偶数\
If m <= 2 Or m Mod 2 <> 0 Then MsgBox \请输入大于2的偶数\ ReDim p(1) p(1) = 2 n = 1
For i = 3 To m - 2 Step 2 If Prime(i) Then n = n + 1
ReDim Preserve p(n) p(n) = i End If Next i
For i = 1 To n For j = 1 To n
If p(i) + p(j) = m Then
Print m & \ flg = True Exit For End If Next j
If flg = True Then Exit For Next i End Sub
2、求组合数Cn?
mn!（n>=m），程序中必须包含一个求阶乘的通用过程。 m!(n?m)!Private Function Fact(a As Integer) As Long If a = 0 Or a = 1 Then Fact = 1 Else
Fact = a * Fact(a - 1) End If
End Function
Private Sub Command1_Click()
Dim n As Integer, m As Integer, result As Single n = Val(Text1.Text) m = Val(Text2.Text) If n >= m Then
result = Fact(n) / Fact(m) / Fact(n - m) Text3.Text = result Else
MsgBox \要求n>=m,请重新输入\ Text1.Text = \ Text2.Text = \ Text1.SetFocus End If End Sub
Private Sub Command2_Click() Text1.Text = \ Text2.Text = \ Text3.Text = \ Text1.SetFocus End Sub 3、编写一个查找10到300之间所有同构数的程序，程序中必须包含一个判定某数是否是同构数的Function过程Istgs。若一个数出现在自己平方数的右端，则此数为同构数。如5在52=25的右端，25在252=625的右端，故5和25为同构数。
Private Function Istgs(n As Integer) As Boolean Dim s As String, L As Integer L = Len(CStr(n)) s = CStr(n ^ 2)
If Right(s, L) = n Then Istgs = True End Function
Private Sub Command1_Click() Dim n As Integer For n = 10 To 300
If Istgs(n) Then List1.AddItem n & \ Next n End Sub
Private Sub Command2_Click() End End Sub
4、编写程序，随机生成一个由三位正整数组成的3行4列的数组，求数组每一行的最大元素及其所在列号，程序中必须包含一个求一行中最大元素及其所在列号的通用过程。（若一行中有多个最大元素则取其中之一即可）
Private Sub CmdDisp_Click()
Dim a(3, 4) As Integer, i As Integer, j As Integer Dim m As Integer, mj As Integer Randomize For i = 1 To 3 For j = 1 To 4
a(i, j) = Int(900 * Rnd + 100) Print a(i, j); Next j Print Next i
For i = 1 To 3 m = 0
Call max(a, i, m, mj)
Print \第\行最大值为\在第\列\ Next i End Sub
Private Sub max(a() As Integer, i As Integer, m As Integer, maxj As Integer) Dim j As Integer m = a(i, 1): maxj = 1
For j = 2 To UBound(a, 2) If a(i, j) > m Then m = a(i, j) maxj = j End If Next j End Sub
Private Sub CmdEnd_Click() End End Sub
5、一个整数N的因子和（不包括N）等于N，则N被成为完全数。例如，28=1+2+4+7+14，28是完全数。编写程序验证：介于10到10000之间的完全数，把它们的各位数字加起来得到一个数，再把这个数的各位数字加起来又得到一个数，一直做下去，直到得到一个一位数，这个数是1，程序中必须包含一个判定某数是否是完全数的过程。例如，28的各位数字加起来得到一个数10，再把10这个数的各位数字加起来又得到一个数是1。
Private Function IsWqs(n As Integer) As Boolean Dim sum As Integer, i As Integer For i = 1 To n / 2
If n Mod i = 0 Then sum = sum + i Next i
If sum = n Then IsWqs = True End Function
Private Sub Command1_Click() Dim n As Integer Dim sum As Integer For n = 10 To 10000 If IsWqs(n) Then t = n
Print t; \ Do
sum = 0
For i = 1 To Len(t) - 1
sum = sum + Mid(CStr(t), i, 1) Print Mid(CStr(t), i, 1); \ Next i
sum = sum + Mid(CStr(t), i, 1) If sum <> 1 Then
Print Mid(CStr(t), i, 1); \ Else
Print Mid(CStr(t), i, 1); \ End If t = sum
Loop Until sum = 1 Print End If