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Why is reading lines from stdin much slower in C++ than Python?
... from stdin using Python and C++ and was shocked to see my C++ code run an order of magnitude slower than the equivalent Python code. Since my C++ is rusty and I'm not yet an expert Pythonista, please tell me if I'm doing something wrong or if I'm misunderstanding something.
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Generate array of all letters and digits
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[*('a'..'z'), *('0'..'9')] # doesn't work in Ruby 1.8
or
('a'..'z').to_a + ('0'..'9').to_a # works in 1.8 and 1.9
or
(0...36).map{ |i| i.to_s 36 }
(the Integer#to_s method converts a number to a string representing it in a desired numeral system)
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The Ruby %r{ } expression
...r}
is equivalent to:
/\/home\/user/
This is only a syntax commodity, for legibility.
Edit:
Note that you can use almost any non-alphabetic character pair instead of '{}'.
These variants work just as well:
%r!/home/user!
%r'/home/user'
%r(/home/user)
Edit 2:
Note that the %r{}x variant ign...
Regular expression to stop at first match
...acters as possible:
/location="(.*?)"/
Adding a ? on a quantifier (?, * or +) makes it non-greedy.
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Best Practice for Forcing Garbage Collection in C#
...y experience it seems that most people will tell you that it is unwise to force a garbage collection but in some cases where you are working with large objects that don't always get collected in the 0 generation but where memory is an issue, is it ok to force the collect? Is there a best practice o...
How to center a Window in Java?
What's the easiest way to centre a java.awt.Window , such as a JFrame or a JDialog ?
16 Answers
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Image width/height as an attribute or in CSS? [duplicate]
What's the "correct" semantic way to specify image height and width? In CSS...
12 Answers
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Control the size of points in an R scatterplot?
...e too small, but pch=19 to be too fat. Is there something in the middle or some way to scale the dots down somehow?
3 An...
insert vs emplace vs operator[] in c++ map
I'm using maps for the first time and I realized that there are many ways to insert an element. You can use emplace() , operator[] or insert() , plus variants like using value_type or make_pair . While there is a lot of information about all of them and questions about particular cases, I sti...
What does the Q_OBJECT macro do? Why do all Qt objects need this macro?
... macro Q_OBJECT as the first line. What is the purpose of this preprocessor macro?
6 Answers
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