数组a为一组正整数,奇数在前,偶数在后。奇数与偶数已分别按升序排序。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程序段如下:
i = 1: j = 10 Key = Val(Text1.Text) Do While i <= j m = (i + j) \ 2 If a(m) = Key Then Exit Do 'Exit Do表示退出循环 If Key Mod 2 = 1 And a(m) Mod 2 = 0 Then (1) ElseIf Key Mod 2 = 0 And a(m) Mod 2 = 1 Then (2) Else (3) End If LoopIf i > j Then s = "没有找到!" Else s = "位置:" + Str(m) Text2.Text = s
上述程序中方框处可选语句为: ①i = m + 1 ②j = m - 1 ③If Key < a(m) Then j = m - 1 Else i = m + 1 则(1)、(2)、(3)处语句依次是
①、③、②
②、①、③
③、②、①