在此代码段中使用Option Explicit
Sub HighlightDuplicates()
Dim ws As Worksheet, t0 As Single, t1 As Single
Set ws = ThisWorkbook.Sheets("Sheet1")
t0 = Timer
'Step 4: Otherwise, a cell should not be highlighted.
ws.Cells.ClearFormats
Const RANGE_A As String = "B1:E2000"
Const RANGE_B As String = "G1:G2000"
Const RANGE_C As String = "I1:AH2000"
Dim dictA As Object, dictB As Object, dictC As Object
Set dictA = CreateObject("Scripting.Dictionary")
Set dictB = CreateObject("Scripting.Dictionary")
Set dictC = CreateObject("Scripting.Dictionary")
Call buildDict(dictA, ws.Range(RANGE_A))
Call buildDict(dictB, ws.Range(RANGE_B))
Call buildDict(dictC, ws.Range(RANGE_C))
'Step 1: If a cell appears in Range A and Range C highlighted yellow.
'Step 2: Then, if a cell appears in Range A and Range B,
'I want them highlighted green.
Dim cell As Range, key As String
For Each cell In ws.Range(RANGE_A)
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If dictC.exists(key) Then cell.Interior.Color = vbYellow
If dictB.exists(key) Then cell.Interior.Color = vbGreen
End If
Next
For Each cell In ws.Range(RANGE_C)
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If dictA.exists(key) Then cell.Interior.Color = vbYellow
End If
Next
For Each cell In ws.Range(RANGE_B)
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If dictA.exists(key) Then cell.Interior.Color = vbGreen
End If
Next
'Step 3: Then, if a cell appears in Range B and more than twice in Range C,
'I want them highlighted red.
For Each cell In ws.Range(RANGE_B)
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If dictC.exists(key) Then
If dictC.Item(key) > 2 * dictB.Item(key) Then
cell.Interior.Color = vbRed
End If
End If
End If
Next
For Each cell In ws.Range(RANGE_C)
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If dictB.exists(key) Then
If dictC.Item(key) > 2 * dictB.Item(key) Then
cell.Interior.Color = vbRed
End If
End If
End If
Next
t1 = Timer
MsgBox "Completed in " & Int(t1 - t0) & " seconds"
End Sub
Sub buildDict(ByRef dict, ByRef rng)
Dim cell As Range, key As String
For Each cell In rng
If Len(cell.Value) > 0 Then
key = CStr(cell.Value)
If Not dict.exists(key) Then
dict.Add key, 1
Else
dict.Item(key) = dict.Item(key) + 1
End If
End If
Next
Debug.Print "Keys in " & rng.Address, dict.Count
End Sub
函数的目的是什么
time.sleep()答案 0 :(得分：3)
这是一种尝试在验证密码时引入随机时间延迟的方法，大概是为了对付timing attacks，在这种情况下，攻击者利用错误的密码导致更快的响应这一事实。
我不希望这会有用。 secrets.compare_digest()已经采取一切适当措施来减轻定时攻击。如果hashpass和target_hash_pass具有相同的类型（总是字节或者都是字符串）并且长度相等，则通常的定时攻击向量在这里不可用。
但是，可能是作者不相信这两个条件总是正确的。 user_info结构可能包含较短或更长时间的密码散列，或者您可能会得到不同的类型。如果是这样，那么应该直接解决这些问题。
应该注意的是，由于定时攻击会使用不同的密码比较多次尝试之间的统计差异，因此随机噪声只会稍微降低此类攻击的速度；无论网络连接和正常的计算机操作已经增加了什么时间差异，它只会增加更多的噪音。请参阅Can I prevent timing attacks with random delays?和Could a random sleep prevent timing attacks?。更糟糕的是，该代码使用标准的random随机数生成器，该生成器在密码上并不安全，因此，如果确定了足够的攻击者，就可以考虑睡眠的变化。
我强烈建议作者删除该行，在此不提供任何实际的安全性。