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How is a CRC32 checksum calculated?
Maybe I'm just not seeing it, but CRC32 seems either needlessly complicated, or insufficiently explained anywhere I could find on the web.
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PostgreSQL Crosstab Query
...rd SQL
);
INSERT INTO tbl VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7); -- ('C', 'Active') is missing
Simple form - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM ...
Implementing slicing in __getitem__
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121
The __getitem__() method will receive a slice object when the object is sliced. Simply look at ...
BaseException.message deprecated in Python 2.6
I get a warning that BaseException.message is deprecated in Python 2.6 when I use the following user-defined exception:
8 A...
how to concatenate two dictionaries to create a new one in Python? [duplicate]
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279
Slowest and doesn't work in Python3: concatenate the items and call dict on the resulting lis...
How to compare two floating point numbers in Bash?
...e conveniently using Bash's numeric context:
if (( $(echo "$num1 > $num2" |bc -l) )); then
…
fi
Explanation
Piping through the basic calculator command bc returns either 1 or 0.
The option -l is equivalent to --mathlib; it loads the standard math library.
Enclosing the whole expression ...
Difference between Divide and Conquer Algo and Dynamic Programming
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answered Nov 24 '12 at 5:55
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Why is there no Tree class in .NET?
...ook at C5? It's super-handy and they have several tree implementations (1, 2, 3).
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Flatten an Array of Arrays in Swift
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Swift >= 3.0
reduce:
let numbers = [[1,2,3],[4],[5,6,7,8,9]]
let reduced = numbers.reduce([], +)
flatMap:
let numbers = [[1,2,3],[4],[5,6,7,8,9]]
let flattened = numbers.flatMap { $0 }
joined:
let numbers = [[1,2,3],[4],[5,6,7,8,9]]
let joined = Array(number...
`elif` in list comprehension conditionals
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259
Python's conditional expressions were designed exactly for this sort of use-case:
>>>...