主题：[求助]学习阶段，求老师改正一下代码？

一点进步都没有

Dim dt As DataTable = DataTables("成绩")
Dim dt_d As DataTable = DataTables("淘汰线计算")
dt_d.DataRows.Clear
Dim zyzs As List(Of String) = dt.GetValues("专业组名称")
Dim ttl As Double = 0.1
Dim sum_avg As Double = 0
For Each zy As String In zyzs
    Dim rys As List(Of DataRow) = dt.Select("专业组名称 = '" & zy & "'", "原始成绩")
   
    Dim dr As DataRow = dt_d.AddNew
    dr("专业组名称") = zy
    Dim i As Integer = ttl*rys.Count
    dr("淘汰线分数") = rys(i)("原始成绩")
    sum_avg += rys(i)("原始成绩")
Next
dt_d.ReplaceFor("平均淘汰线", sum_avg / zyzs.count)
For Each dr As DataRow In dt.DataRows
    If dr("原始成绩")> sum_avg / zyzs.count Then  '如果成绩表中的最终成绩大于淘汰线计算表的平平均淘汰线
        dr("等次") ="平均入围"
    Else
        dr("等次") ="平均淘汰"
    End If
Next