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Remove duplicated rows
...for larger data sets
library(microbenchmark)
library(data.table)
set.seed(123)
DF <- as.data.frame(matrix(sample(1e8, 1e5, replace = TRUE), ncol = 10))
DT <- copy(DF)
setDT(DT)
microbenchmark(unique(DF), unique(DT))
# Unit: microseconds
# expr min lq mean median ...
Finding all cycles in a directed graph
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@user1988876 This appears to find all cycles involving a given vertex (which would be start). It starts at that vertex and does a DFS until it gets back to that vertex again, then it knows it found a cycle. But it doesn't actually ...
json_encode sparse PHP array as JSON array, not JSON object
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Mark Amery
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answered Sep 24 '13 at 9:18
Nguyen Van ...
How do I pre-populate a jQuery Datepicker textbox with today's date?
...k and doesn't make jQuery search the DOM twice.
– abc123
Aug 1 '13 at 20:36
1
Great, accepted ans...
What does 'const static' mean in C and C++?
...to static at namespace level (and some gave wrong information). See the C++98 standard section 3.5.3.
First some background:
Translation unit: A source file after the pre-processor (recursively) included all its include files.
Static linkage: A symbol is only available within its translation unit...
How do you check if a certain index exists in a table?
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AdaTheDevAdaTheDev
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...
C++ semantics of `static const` vs `const`
...anks, though I don't think this is a chance in C++17 compared even with C++98, and the question was asked in 2010. Moreover, your answer deals only with static as a linkage specifier (at namespace scope), and the question asked specifically about the semantics in different contexts.
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Simple regular expression for a decimal with a precision of 2
...e
deci_num_checker = re.compile(r"""^[0-9]+(\.[0-9]{1,2})?$""")
valid = ["123.12", "2", "56754", "92929292929292.12", "0.21", "3.1"]
invalid = ["12.1232", "2.23332", "e666.76"]
assert len([deci_num_checker.match(x) != None for x in valid]) == len(valid)
assert [deci_num_checker.match(x) == None fo...
网站伪静态Rewrite重写中文路径时乱码 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...，会发现IE实际查询的网址是“http://zh.wikipedia.org/wiki/%E6%98%A5%E8%8A%82”。也就是说，IE自动将“春节”编码成了“%E6%98%A5%E8%8A%82”。
我们知道，“春”和“节”的utf-8编码分别是“E6 98 A5”和“E8 8A 82”，因此，“%E6%98%A5%E8%8A%82...
How do I replace a git submodule with another repo?
...
123
If the location (URL) of the submodule has changed, then you can simply:
Modify your .gitmod...