题型:综合题 题类:常考题 难易度:普通
浙江省浙南名校联盟2020届高三上学期信息技术第一次(10月)联考试卷
同时,对于多个地址块为 0 的情况时,可以使用“::”号,进行化简。化简原则:
①全 0 块“0000”,可以化简为“0”
②连续多个全0块,可以化简为“::”
③一个IPv6地址中只能出现一个“::”,出现多个全 0块时,“::”要化简最长的一段,没有最长的就将最左侧的一段化简为“::”
④“::”可以出现在地址开头或结尾具体示例如下:
化简前 |
化简后 |
ABCD:0000:2345:0000:ABCD:0000:2345:0000 |
ABCD:0:2345:0:ABCD:0:2345:0 |
FBCD:EF01:0000:0000:0000:0000:0000:6789 |
FBCD:EF01::6789 |
BBCD:0000:0000:0000:ABCD:0000:0000:6789 |
BBCD::ABCD:0:0:6789 |
0000:0000:0000:0000:0000:0000:0000:0001 |
::1 |
2001:0000:0000:0000:0000:0000:0000:0000 |
2001:: |
程序界面如图所示:
实现上述功能的VB程序如下,请回答下列问题:
Private Sub Text1_Change()
Dim a(1 To 8) As String, ipstr As String, ips As String
Dim lenth As Integer, max_lenth As Integer, start As Integer
ipstr = Text1.Text
For i = 1 To 8
a(i) = ① ' 将IPv6分段存入数组a
Next i
'对数组进行处理,如果字母或非零数字开头,则不用处理;如果全是数字,则压缩成 0,如果前导为 0,则去掉,处理完毕存回数组。
'///------ 处理过程略------/////
'如果只有一串,则将该串“0”用“::”代替,如果不止一串,则将最长的一串“0”简化为“::”,如果有连续 0,则将左边的一串零简化,右侧保留。
max_lenth = 0
For i = 1 To 7
If ② Then
lenth = lenth + 1
Else
If lenth > max_lenth Then
max_lenth = lenth: start = i - lenth: lenth = 0
End If
End If
Next i
If lenth > max_lenth Then max_lenth = lenth: start = i - lenth
'根据连续0串的位置确定输出简化后的结果
ips = ""
If start = 1 And max_lenth = 7 Then '开头是0且全0
ips = "::"
ElseIf start = 1 Then '开头是0但不全为0
ips = "::"
For i = start + max_lenth + 1 To 7
ips = ips + a(i) + ":"
Next i
ips = ips + a(i)
ElseIf start > 1 And start + max_lenth = 8 Then '开头不是0但0到最后
For i = 1 To start - 1
ips = ips + a(i) + ":"
Next i
ips = ips + ":"
ElseIf start > 1 Then '开头不是0且0不到最后
For i = 1 To start - 1
ips = ips + a(i) + ":"
Next i
ips = ips + ":"
For i = ③ To 7
ips = ips + a(i) + ":"
Next i
ips = ips + a(i)
Else '无连续0出现
For i = 1 To 7
ips = ips + a(i) + ":"
Next i
ips = ips + a(i)
End If
Text2.Text = ips End Sub
① ② ③
试题篮