题型:综合题 题类:常考题 难易度:普通
【bj】高中信息技术综合库——枚举算法及程序实现1
实现上述功能的VB代码如下。
Dim a(1 To 50) As Integer
Private sub Command1_Click()
Dim i As Integer
k=0: i=3
Do While i<= 100
If Not prime(i) Then
k=k+1
End If
i=i+2
Loop
For i=2 To k
If Then
List1 AddItem Str(a(i-1))+"和"+ Str(a(i))
End if
Next i
End Sub
Function prime (x As Integer)As Boolean
prime=False
For i=2 To Int(sar(x))
If x Mod i=0 Then
prime=True
Exit for
End If
Next i
End Function
程序代码如下:
Private Sub Command1_Click()
Dim i As Integer
List1.Clear '清除列表框内容
For i = 3 To 97 ___①___ If f(i) And f(i+2)=true Then List1.AddItem Str(i) + " 和 " + Str(i + 2) End If Next i |
End Sub
Private Function f(x As Integer) As Boolean '判断是否为素数,若是返回true,若不是则返回false
………
End Function
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