VB-完形一.doc

三、程序完形7本程序的功能是求下面数列前n项之和：Option ExplicitPrivate Sub Command1_Click() Dim x As Single, s As Single Dim n As Integer, i As Integer x = InputBox(输入X:, 求数列和, 1) n = InputBox(输入N:, 求数列和, 1) For i = 1 To n s = s + fun(x, i) Next i Label1.Caption = （17） Text1 = sEnd SubPrivate Function fun(x As Single, n As Integer) As Single （18） p = 1 For i = 1 To n （19） Next i fun = x (2 * n - 1) * pEnd Function8下面程序的功能为：读取一个文本文件的全部内容，并统计文件中各个字母出现的个数。Option ExplicitPrivate Sub Command1_Click() Dim alpha(26) As Integer, n As Integer, s As String Dim i As Integer, st As String Open c:kav2003readme.txt For Input As #11 Do While Not EOF(11) （20） s = UCase(s) st = st & s If s = A And s = Z Then n = （21） alpha(n) = alpha(n) + 1 End If Loop Text1 = st For i = 1 To 26 If alpha(i) 0 Then List1.AddItem Chr(i + 64) & : & CStr(alpha(i) End If Next i CloseEnd Sub 9下面程序的功能是依次将给定字符串A中的字符逐个插入到字符串B中，插入位置是字符串B中第1个与其相同的字符之后（不分大小写），若B中无相同字符，则依次插入到B的末尾。Private Sub Command1_Click() Dim st1 As String, st2 As String st1 = Text1.Text : st2 = Text2.Text Call inst(st1, st2) Text3 = st2End SubPrivate Sub inst(s1 As String, s2 As String) Dim i As Integer, p As String, n As Integer, n1 As Integer For i = 1 To Len(s1) p = Mid(s1, i, 1) If p = A And p = a And p = z Then （23） n1 = InStr(s2, p) （24） Else MsgBox 字符串A中含有非字母字符！, vbOKOnly, 合并字符串 Exit Sub End If Next iEnd SubPrivate Sub ins(s As String, p As String, n As Integer, k As Integer) If n 0 And k = 0 Or n 0 And k 0 And n k Then s = Left(s, n) & p & Right(s, Len(s) - n) ElseIf （25） Then s = Left(s, k) & p & Right(s, Len(s) - k) Else s = s & p End IfEnd Sub10下面是一个采用拉锯式排序法对数组元素按升序进行排序的程序，所谓“拉锯式排序法”是这一遍把最小的元素从下到上送到最上的位置，下一遍则是从上到下把最大的元素送到最下的位置。Option Base 1Private Sub Command1_Click() Dim a(10) As Integer, i As Integer For i = 1 To 10 a(i) = Int(Rnd * 10) + 1 Text1 = Text1 & Str(a(i) Next i Call shaker_sort(a) For i = 1 To 10 Text2 = Text2 & Str(a(i) Next iEnd SubPrivate Sub shaker_sort(k() As Integer) Dim i As Integer, c As Integer, b As Integer, d As Integer Dim t As Integer c = 1 d = （26） Do For （27） Step -1 If k(i - 1) k(i) Then t = k(i - 1): k(i - 1) = k(i): k(i) = t End If Next i （28） For i = c To d If （29） Then t = k(i - 1): k(i - 1) = k(i): k(i) = t End If Next i d = d - 1 Loop While （30） End Sub参考答案：17S( & CStr(x) & , & CStr(n) & )=18Dim i As Integer, p As Single19p = p * i / (2 * i)20Input(1, 11)21Asc(s) - Asc(A) + 121 n1 = InStr(s2, LCase(p)23n = InStr(s2, UCase