(加试题)小明编写了一个VB程序,功能如下:在文本框Text1中输入一段英文,并在文本框Text2中输入英文段落中的某个单词(或字符串),单击“最大间距”按钮(Command1)后,在文本框Text3中显示该单词在文中某两次出现的最大间距,若只出现一次或不出现则显示值为0。程序运行界面如下图所示:
实现上述功能的VB程序如下:
Private Sub Command1_Click()
Dim a(1 To 1000) As String '数组a存储文中出现该指定单词(或字符串)的各个位置
Dim s As String, c As String ,ch As String
Dim n As Integer, max As Integer, i As Integer
s = Text1.Text
c = Text2.Text
n = 0: Max = 0
For i = 1 To Len(s) - Len(c) + 1
ch = ①
If ch = c Then
n = n + 1
a(n) = i
If n >= 2 Then
If a(n) - a(n - 1) - Len(c) > Max Then Max = a(n) - a(n - 1) - Len(c)
End If
End If
Next i
Text3.Text = ②
End Sub
以上程序段运行时,为了实现上述功能,划线处①和②应填入的代码分别为:
(1)_______________________________; (2)_______________________________
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2