江苏省二级VB改错题真题解析.ppt

1、江苏省二级VB改错题解析,宿迁学院 计算机科学系 王学军,2008年（秋）01,本程序的功能：随机生成一个有n个元素的数组（n由InputBox函数输入），找出其中的最大元素并将它删除，再输出删除后的数组。,2008年（秋）01,Option Explicit Option Base 1 Dim a() As Integer, n As Integer Private Sub Command1_Click() Dim i As Integer n = InputBox(请输入数组元素个数, , 10) ReDim a(n) For i = 1 To n a(i) = Int(Rnd * 100

2、) + 1 Text1 = Text1 & Str(a(i) Next i Call Lookup(a) For i = 1 To UBound(a) Text2 = Text2 & Str(a(i) Next i End Sub Private Sub Lookup(a() As Integer) Dim Maxv As Integer, maxp As Integer, i As Integer Maxv = a(1): maxp = 1 For i = 2 To n If a(i) Maxv Then Maxv = a(i): maxp = i End If Next i Call mo

3、ve_f(a, maxp) End Subk,Private Sub move_f(a() As Integer, k As Integer) Dim i As Integer For i = k+1 To UBound(a) a(i) = a(i + 1) Next i ReDim a(UBound(a) - 1) End Sub,Preserve,k to UBound(a)-1,2008年（秋）02,本程序的功能：查找80150范围内的特殊十进制数，其特点是该十进制数对应的八进制数为回文数。例如，十进制数105对应的八进制数为151，151属于回文数，所以105就是符合要求的数。,200

4、8年（秋）02,Option Explicit Private Sub Command1_Click() Dim i As Integer, hw As String, fg As Boolean Dim st As String For i = 80 To 150 fg = False Call hw8(i, hw, fg) If fg Then st = CStr(i) & = & hw & &O List1.AddItem st End If Next i End Sub Private Sub hw8(n As Integer, hw As String, f As Boolean)

5、Dim k As Integer, st() As String * 1, i As Integer hw = Do k = k + 1 ReDim Preserve st(k) st(k) = n Mod 8 hw = st(k) & hw n = n 8 Loop Until n st(UBound(st) - i + 1) Then Exit For Next i f = True End Sub,ByVal n,n = 0,Exit Sub,2008年（秋）03,本程序的功能是将密文解密。密文中被非数字字符分隔的连续的数字是五进制数，每个五进制数对应一个明文字符的ASCII代码。例如，

6、五进制数242对应的ASCII代码值是72，也就是字母“H”，密文本尾以非数字字符结束。,2008年（秋）03,Option Explicit Option Base 1 Private Sub Command1_Click() Dim mw As String, st As String, i As Integer Dim p As String, t() As String, k As Integer mw = Text1 For i = 1 To Len(mw) p = Mid(mw, i, 1) st = If p = 0 And p 0 Then k = k + 1 ReDim t(

7、k) t(k) = st End If Next i For i = 1 To UBound(t) k = convert(t(i) st = st & Chr(k) Next i Text2 = st End Sub,Preserve,Step -1,Private Function convert(p As String) As Integer Dim i As Integer, k As Integer, n As Integer For i = Len(p) To 1 n = n + Val(Mid(p, i, 1) * 5 k k = k + 1 Next i convert = n

8、 End Function,2008年（秋）04,本程序的功能是：查找8001200范围内的所有具有两个相同数字的素数。例如，811、877等都是符合要求的数据。,2008年（秋）04,Option Explicit Private Sub Command1_Click() Dim i As Integer For i = 800 To 1200 If validate(i) And prime(i) Then List1.AddItem i End If Next i End Sub Private Function prime(n As Integer) As Boolean Dim i

9、As Integer For i = 2 To Sqr(n) If n Mod i = 0 Then Exit For Next i prime = True End Function,Preserve,Function,Private Function validate(n As Integer) As Boolean Dim num() As Integer, k As Integer Dim i As Integer, j As Integer Do k = k + 1 ReDim num(k) num(k) = n Mod 10 n = n 10 Loop Until n = 0 k

10、= 0 For i = 1 To UBound(num) - 1 For j = i + 1 To UBound(num) If num(i) = num(j) Then k = k + 1 Next j Next i If k = 1 Then validate = True End Function,ByVal n,2008年（秋）05,本程序的功能是：查找100以内有三个不同质因子的所有整数。,2008年（秋）05,Option Explicit Option Base 1 Private Sub Command1_Click() Dim i As Integer, j As Integ

11、er Dim a() As Integer, s As String For i = 2 To 100 Call zys(i, a) If UBound(a) = 3 Then s = i & 的质因子： For j = 1 To UBound(a) s = s & Str(a(j) Next j List1.AddItem s End If Next i End Sub,ReDim Preserve a(i),x = 1,Private Sub zys(x As Integer, a() As Integer) Dim i As Integer, j As Integer j = 2 Do

12、If x Mod j = 0 Then i = i + 1 ReDim a(i) a(i) = j x = x j Do While x Mod j = 0 x = x j Loop Else j = j + 1 End If Loop Until x = 0 End Sub,ByVal x,2008年（秋）06,本程序的功能是：在自然数序列中，依次找出指定个数的连续合数。例如，输入n=5，则可得到24、25、26、27、28。所谓合数是指除了1和自身整除之外，还可被其他数整除的数（函数np的功能是判断一个数是否是合数）。,2008年（秋）06,Option Explicit Option B

13、ase 1 Private Sub Command1_Click() Dim k As Integer, n As Integer, i As Integer Dim hs() As Integer n = Text1 k = 2 Do Until i = n If np(k) Then i = i + 1 ReDim hs(i) hs(i) = k ElseIf i n Then i = 0 End If Erase hs k = k + 1 Loop For i = 1 To n Text2 = Text2 & Str(hs(i) Next i End Sub,Preserve,For,P

14、rivate Function np(n As Integer) As Boolean Dim i As Integer For i = 2 To n-1 If n Mod i = 0 Then Exit Function Next i If i = n - 1 Then np = True End Function,2008年（秋）07,本程序的功能是：依次求出输入字符串中所有由相同字符组成的子串的长度。,2008年（秋）07,Option Explicit Private Sub Command1_Click() Dim s As String, st() As String, i As Integer s = Text1 Call stati(s, st) For i = 1 To UBound(st) List1.AddItem Left(st(i), 1) & - & Len(st(i) Next i End Sub,stati,Mid(s, i ,1),Private Sub statii(s As String, st() As String) Dim i As Integer, k As Integer Dim p As String * 1, a