若一个数是某个整数的平方,则该数被称为完全平方数。下列程序段用于找出字符串中用逗号分割的完全平方数。部分程序代码如下:
Dim tmp As Single ,s As String ,ch As String ,i As Integer s = "1,20,36,29,3,"
tmp = 0
For i = 1 To Len(s)
ch = Mid(s, i, 1)
If ch <> "," Then
Else
If Then
List1.AddItem Str(tmp)
End If
tmp = 0
End If
Next i
上述程序段中横线处可选语句为:
① tmp = tmp * 10 + Val(ch)
② tmp = tmp + ch
③ Sqr(tmp) ^ 2 = tmp
④ Int(Sqr(tmp)) = Sqr(tmp)
则方框处处语句依次为: ( )