(加试题)数组a中存储的是一组正整数,特征是:①以三个数为一组的话,每组中任意一个数都比前面一组中的任意一个数要大;②每组中三个数依次递减;③数组中数的总个数为3的倍数。依据对分查找思想,设计一个在数组a中查找数据key的程序。实现该功能的VB程序如下,但加框处代码有错,请改正。
8
| 5
| 3
| 17
| 15
| 10
| 32
| 23
| 18
| 53
| 43
| 37
| 82
| 72
| 63
| ……
|
Private Sub Command1_Click()
Const n = 15
Dim a(1 To n) As Integer, search As Integer, key As Integer
Dim i As Integer, j As Integer, m As Integer
'读取一组正整数,按上述规则存入数组a中,代码略。
key = Val(Text1.Text)
i = 1: j = n: search = 0
Do While i <= j
m = (i + j) \ 2
If m Mod 3 <> 0 Then m= m -2 '(1) 把m调整到三个一组的最后一个数的位置
If key = a(m) Then
search = m : Exit Do
ElseIf key < a(m) Then
j = m - 3
ElseIf key <= a(m - 2) Then '(2)
i = m + 1
ElseIf key = a(m - 2) Then
search = m - 2 : Exit Do
ElseIf key = a(m - 1) Then
search = m - 1 : Exit Do
Else
search = 0 : Exit Do
End If
Loop
If search <> 0 Then
Text2.Text = Str(search)
Else
Text2.Text = "找不到"
End If
End Sub
加框处代码应修改为:(1)
【小题1】 (2)
【小题2】