Dim n As Integer, x(1000) As Integer, y(1000) As Integer

Private Sub Command2_Click( )

'生成n个点的坐标,并按要求排序，代码略

'第i个点的坐标保存在x(i)和y(i)并显示在List1 中

End Sub

Private Sub Command2_Click()

    Dim i As Integer, j As Integer

    For i=1 To n

        For j=i+1 To n

            If  Then

                If search(x(i), y(j)) = True And search() = True Then

                    '将4个坐标点显示在List2中,代码略

                    cnt=cnt+1

                End If

            End If

        Next j

    Next i

    List2AddItem "总共有" + Str(cnt) + "个符合要求的正方形"

End Sub

Function search(x As Integer, sy As Integer) As Boolean

    Dim L As Integer, R As Integer, m As Integer

    search = False: L= 1: R= n

    Do While L<= R

        m=(L+R)\2

        If sx < x(m) Or  Then

            R=m-1

        ElseIf x> x(m) Or x= x(m) And ey > y(m) Then

            L=m+1

        Else

            search = True: Exit Do

        End If

    Loop

End Function