本地部署 Moss

how MOSS works

Variable rename is of no use.
Whitespace insensitivity
Whitespace insensitivity In matching text files, matches should be unaffected by such things as extra whitespace, capitalization, punctuation, etc. In other domains the notion of what strings should be equal is different—for example, in matching software text it is desirable to make matching insensitive to variable names.
Noise suppression
Discovering short matches, such as the fact that the word the appears in two different documents, is uninteresting. Any match must be large enough to imply that the material has been copied and is not simply a common word or idiom of the language in which documents are written.
Position independence
Coarse-grained permutation of the contents of a document (e.g., scrambling the order of paragraphs) should not affect the set of discovered matches. Adding to a document should not affect the set of matches in the original portion of the new document. Removing part of a document should not affect the set of matches in the portion that remains.

Typically, a potential case of plagiarism will result in over 50% matching, while a non-plagiarism case will be around 10-15% matching.

逻辑逆转 a is not None -> not a is None, a>b -> b+0<a+7*zero
冗余逻辑 a and b and True or False

1 2	def blackhole(a, b=None,c=None,d=None): return a

for-enumerate

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for i in range(0,10)
for idx,i in enumerate(range(0,10))

不同的 abstract tree
不同的控制流图与数据流图
不同的 semantic vector