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Java HashMap performance optimization / alternative
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As many people pointed out the hashCode() method was to blame. It was only generating around 20,000 codes for 26 million distinct objects. That is an average of 1,300 objects per hash bucket = very very bad. However if I turn the two arrays into a number in base 52 I am guaranteed to get...
Why would a JavaScript variable start with a dollar sign? [duplicate]
I quite often see JavaScript with variables that start with a dollar sign. When/why would you choose to prefix a variable in this way?
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Remove duplicates from a List in C#
... for (int i = 0; i < 5; i++)
{
// Populate numbers with just even numbers.
evenNumbers.Add(i * 2);
// Populate oddNumbers with just odd numbers.
oddNumbers.Add((i * 2) + 1);
}
Console.Write("evenNumbers contains {0} element...
Is there a .NET/C# wrapper for SQLite? [closed]
I'd sort of like to use SQLite from within C#.Net, but I can't seem to find an appropriate library. Is there one? An official one? Are there other ways to use SQLite than with a wrapper?
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How can I write output from a unit test?
Any call in my unit tests to either Debug.Write(line) or Console.Write(Line) simply gets skipped over while debugging and the output is never printed. Calls to these functions from within classes I'm using work fine.
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How do I check if a C++ std::string starts with a certain string, and convert a substring to an int?
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Use an overload of rfind which has the pos parameter:
std::string s = "tititoto";
if (s.rfind("titi", 0) == 0) {
// s starts with prefix
}
Who needs anything else? Pure STL!
Many have misread this to mean "search backwards through the whole string looking for the prefix". That would give the...
UISegmentedControl below UINavigationbar in iOS 7
...w do I make a UISegmentedControl as a part of an UINavigationBar below it? Is it connected to the UINavigationBar or is it a complete separate view just added as a subview to the UINavigationController 's view controller. Looks like it is part of the UINavigationBar since there is a shadow ...
How do I build a graphical user interface in C++? [closed]
... the command line interface and the only other language I have experience with is PHP which doesn't support GUIs.
8 Answer...
Cannot use object of type stdClass as array?
I get a strange error using json_decode() . It decode correctly the data (I saw it using print_r ), but when I try to access to info inside the array I get:
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How does C compute sin() and other math functions?
...e that actually runs when you call sin() on a typical x86-64 Linux system. It is apparently faster than the fsin assembly instruction. Source code: sysdeps/ieee754/dbl-64/s_sin.c, look for __sin (double x).
This code is very complex. No one software algorithm is as fast as possible and also accurat...