VB编程：对数组进行二分查找

运行效果

程序代码

Option Explicit
Dim myarray(100) As Integer           '定义数组，下标0-100，数组元素为101个

Private Sub Command1_Click()
    Dim low, high, mid, n As Integer
    Dim found As Boolean
    low = 0
    n = 0
    high = UBound(myarray)
    found = False
    mid = CInt((high + low) / 2)      '转换为整型，小数部分四舍五入，避免下标出现小数
    Do While Not found And (high >= low)
        n = n + 1
        If CInt(Text1.Text) = myarray(mid) Then   ''查找值和当前中间值比较，相等输出
            found = True
            Label1.Caption = "查询次数：" & n & vbCrLf & _
                             "查询数值：" & myarray(mid) & vbCrLf & _
                             "数组下标：" & mid
            Exit Do
        ElseIf CInt(Text1.Text) < myarray(mid) Then  '查找值和当前中间值比较，小了
            high = mid - 1
        Else                                   '查找值和当前中间值比较，大了
            low = mid + 1
        End If
    mid = CInt((high + low) / 2)
    Loop
End Sub

Private Sub Form_load()
 Dim i As Integer
    For i = 0 To UBound(myarray)                '给数组赋值
        myarray(i) = i
        Print myarray(i)
    Next i
End Sub

学习心得

1、二分法查找的思想就是：先取中间值作比较，看大了还是小了，大了就往下取数，小了就往上取数。这样逐步缩小查找范围，就不用每个数都去做比较。适用于有序数组，确实能提高计算效率，是一个很不错的思维方式。