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Determining complexity for recursive functions (Big O notation)
...4, even though the result is the same, shouldn't the induction be the following? T(n) = a + 2T(n-1) = a + 2a + 4T(n-1) = 3a + 4a + 8T(n-1) = a * (2^n - 1) + 2^n * T(0) = a * (2^n - 1) + b * 2^n = (a + b) * 2^n - a = O(2^n)
– Snowfish
Jan 3 at 22:59
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Why doesn't C++ have a garbage collector?
...the paper made a good job of introducing the concepts one at a time and showing the evolution of the algorithm from the "simple" version to the full-fledged one. Recommended reading if only I could put my hands back on the PDF file...
2. Resources Acquisition Is Initialization (RAII)
It's a common...
Git Symlinks in Windows
Our developers use a mix of Windows and Unix based OS's. Therefore, symlinks created on Unix machines become a problem for Windows developers. In windows (msysgit), the symlink is converted to a text file with a path to the file it points to. Instead, I'd like to convert the symlink into an actual W...
C++ performance challenge: integer to std::string conversion
...--- 10.230 s
ergosys: 101.42 MB/sec --- 9.860 s
MSVC 2010 64-bit /Ox on Windows 7 64-bit, Core i5
hopman_fun: 127 MB/sec --- 7.874 s
hopman_fast: 259 MB/sec --- 3.861 s
voigt: 221.435 MB/sec --- 4.516 s
user_voigt_timo: 195.695 MB/sec --- 5.110 s
timo: 253.165 MB/sec --- 3.950 s
user: 212....
What's the fastest way to merge/join data.frames in R?
... issue? For example I'm guessing that SEM=Scanning electron microscope? Knowing more about the application makes it more interesting to us and helps us prioritise.
– Matt Dowle
Aug 12 '14 at 12:00
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lenses, fclabels, data-accessor - which library for structure access and mutation is better
... putting twice is the same as putting once, or rather, that the second put wins.
put l b1 (put l b2 a) = put l b1 a
Note, that the type system isn't sufficient to check these laws for you, so you need to ensure them yourself no matter what lens implementation you use.
Many of these libraries als...
Java “Virtual Machine” vs. Python “Interpreter” parlance?
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@S.Lott Because it's always good to win arguments with colleagues. ;)
– Qix - MONICA WAS MISTREATED
Oct 6 '14 at 3:50
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How do you convert a byte array to a hexadecimal string, and vice versa?
... faster than {IEnumerable}.Aggregate, for instance, but BitConverter still wins.
Update (2012-04-03)
Added Mykroft's SoapHexBinary answer to analysis, which took over third place.
Update (2013-01-15)
Added CodesInChaos's byte manipulation answer, which took over first place (by a large margin on...
Iterator Loop vs index loop [duplicate]
I'm reviewing my knowledge on C++ and I've stumbled upon iterators. One thing I want to know is what makes them so special and I want to know why this:
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How do I find where an exception was thrown in C++?
...and often is, located in a different function/method than the point of throwing. It has also been pointed out to me in the comments (thanks Dan) that it is implementation-defined whether or not the stack is unwound before terminate() is called.
Update: I threw together a Linux test program called t...