首先，分别求出特加密ASCII字符的ASCII码，然后用7位二进制来表示，比如“4”的ASCII码为十进制52，转换为7位二进制为“0110100”

其次，从左至右依次记为第1、2、3....7位，分别把第3、4、5位取反，即0变1， 1变0，至此“0110100”变为“0101000”，将此二进制转换为ASCII码为40，对应的字符为“(”，即“4”经过加密后得到加密字符左括号“(”。

在文本框Text1中输入ASCII字符，单击命令按钮Command，则在文本框Text2中显示经过加密的字符。VB代码如下，程序界面如图所示。

上述加密与解密过程实际上是可以互逆的，请完成下列问题。

图a

图b

Dim n As Integer, i As Integer, left As Integer, right As Integer, m As Integer

Dim a(1 To 10) As String, t As String, key As String n = 6

a(1) = "35": a(2) = "20": a(3) = "18": a(4) = "8": a(5) = "274": a(6) = "47" For i = 1 To n - 1

For j = n To i + 1 Step -1

If a(i) < a(j) Then

t = a(i): a(i) = a(j): a(j) = t

End If

Next j

Next i

key = Text1.Text

left = 1: right = n

Do While left <= right

m = (left + right) \ 2

If a(m) = key Then Exit Do

If a(m) < key Then right = m - 1 Else left = m + 1

Loop

若在文本框 Text1 中输入“212”，则程序运行结束后，m 的值为（  ）

s=56

s1=s\10

s2=s Mod 10

s=s1+s2*10

Print "s="; s