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Callback functions in C++
In C++, when and how do you use a callback function?
10 Answers
10
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How do RVM and rbenv actually work?
I am interested in how RVM and rbenv actually work.
5 Answers
5
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How to reset sequence in postgres and fill id column with new data?
I have a table with over million rows. I need to reset sequence and reassign id column with new values (1, 2, 3, 4... etc...). Is any easy way to do that?
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What's the algorithm to calculate aspect ratio?
...8:1.
If so, what you need to do is find the greatest common divisor (GCD) and divide both values by that. The GCD is the highest number that evenly divides both numbers. So the GCD for 6 and 10 is 2, the GCD for 44 and 99 is 11.
For example, a 1024x768 monitor has a GCD of 256. When you divide bot...
How do I add more members to my ENUM-type column in MySQL?
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Most ALTER TABLE commands will completely rewrite the whole table. Is mysql clever enough to not do that with enum ?
– John
Oct 9 '18 at 22:10
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Concept behind these four lines of tricky C code
...- -------- --------
+ shows the position of the sign; ^ of the exponent, and - of the mantissa (i.e. the value without the exponent).
Since the representation uses binary exponent and mantissa, doubling the number increments the exponent by one. Your program does it precisely 771 times, so the ex...
JOIN queries vs multiple queries
Are JOIN queries faster than several queries? (You run your main query, and then you run many other SELECTs based on the results from your main query)
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How to export all data from table to an insertable sql format?
... in a database (call it A_db ) in Microsoft SQL Server Management Studio, and there are 10 rows.
6 Answers
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Git pre-push hooks
I would like to run a unit-tests before every git push and if tests fails, cancel the push, but I can't even find pre-push hook, there is pre-commit and pre-rebase only.
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How to find and return a duplicate value in array
...s isn't very elegant answer, but I love it. It's beautiful one liner code. And works perfectly fine unless you need to process huge data set.
Looking for faster solution? Here you go!
def find_one_using_hash_map(array)
map = {}
dup = nil
array.each do |v|
map[v] = (map[v] || 0 ) + 1
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