江苏 2025 年（春）上机 Visual Basic 答案一、改错【题目】本程序的功能如下图所示，将输入的一个由数字字符组成的字符串，从第一位、第二位……直到倒数第二位，依次取两位数据，得到一组两位整数输出到列表框 1，再将其中的素数选择出来输出到列表框 2（注意，假如截取到的两位数字，第一位为 0，例如 05，则无效，将其丢弃）。Option ExplicitPrivate Sub Command1_Click() Dim st As String, num() As Integer Dim k As Integer, i As Integer st = Text1 i = 1: k = 1 Do If Mid(st, i, 1) <> "0" Then ReDim Preserve num(k) 'err 无 Preserve num(k) = Val(Mid(st, i, 2)) List1.AddItem num(k) k = k + 1 End If i = i + 1 Loop While i < Len(st) 'err i <= Len(st) For i = 1 To UBound(num) If prime(num(i)) Then List2.AddItem num(i) Next iEnd SubPrivate Function prime(n As Integer) As Boolean Dim i As Integer For i = 2 To Sqr(n) If n Mod i = 0 Then Exit Function 'err Exit For Next i prime = TrueEnd Function二、编程题【题目】编写程序，将 10～5000 之间的一组数据，变换到（0, 1）区间。变换的方法是，找出这组数据中的最大数，用大于它的第一个能被 100 整除的数 n ，分别除以这组数据中的每个数。例如，在下图数据中最大数为 4810，则 n 为 4900，用所有数据除以 4900 进行变换。Option ExplicitOption Base 1Dim a(20) As IntegerPrivate Sub Command1_Click() Dim i As Integer, j As Integer For i = 1 To 20 a(i) = Int(Rnd * (4999 - 10 + 1)) + 10 Text1.Text = Text1 & Str(a(i)) If i Mod 5 = 0 Then Text1.Text = Text1 & vbCrLf Next iEnd SubPrivate Sub Command2_Click() Dim i As Integer, n As Integer n = ((maxv \ 100) + 1) * 100 For i = 1 To 20 List1.AddItem a(i) & "---" & CSng(a(i) / n) Next iEnd SubPrivate Function maxv() As Integer Dim i As Integer maxv = a(1) For i = 2 To 20 If maxv < a(i) Then maxv = a(i) Next iEnd FunctionPrivate Sub Command3_Click() Text1.Text = "" List1.Clear Command1.SetFocusEnd Sub
