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Why is the minimalist, example Haskell quicksort not a “true” quicksort?
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The true quicksort has two beautiful aspects:
Divide and conquer: break the problem into two smaller problems.
Partition the elements in-place.
The short Haskell example demonstrates (1), but not (2). How (2) is done may not be obvious if you don't already know the technique!...
Access to Modified Closure (2)
...need to re-declare a variable inside the foreach - otherwise it is shared, and all your handlers will use the last string:
foreach (string list in lists)
{
string tmp = list;
Button btn = new Button();
btn.Click += new EventHandler(delegate { MessageBox.Show(tmp); });
}
Significantly,...
What is the difference between Ruby 1.8 and Ruby 1.9
...m not clear on the differences between the "current" version of Ruby (1.8) and the "new" version (1.9). Is there an "easy" or a "simple" explanation of the differences and why it is so different?
...
Alphabet range in Python
...', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
And to do it with range
>>> list(map(chr, range(97, 123))) #or list(map(chr, range(ord('a'), ord('z')+1)))
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v...
Is calculating an MD5 hash less CPU intensive than SHA family functions?
Is calculating an MD5 hash less CPU intensive than SHA-1 or SHA-2 on "standard" laptop x86 hardware? I'm interested in general information, not specific to a certain chip.
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Usage of sys.stdout.flush() method
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Python's standard out is buffered (meaning that it collects some of the data "written" to standard out before it writes it to the terminal). Calling sys.stdout.flush() forces it to "flush" the buffer, meaning that it will write everythi...
Check whether a variable is a string in Ruby
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I think you are looking for instance_of?. is_a? and kind_of? will return true for instances from derived classes.
class X < String
end
foo = X.new
foo.is_a? String # true
foo.kind_of? String # true
foo.instance_of? String # false
foo.instance_of? X ...
Why does this (null || !TryParse) conditional result in “use of unassigned local variable”?
...se, so I'm set for now. Thanks for your insight!
– Brandon Martinez
Apr 30 '13 at 17:39
4
@NominS...
Can you create nested WITH clauses for Common Table Expressions?
...wered Sep 11 '09 at 22:12
David AndresDavid Andres
28.8k77 gold badges4141 silver badges3535 bronze badges
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std::back_inserter for a std::set?
...f an element is determined by the comparator of the set. Use std::inserter and pass it .begin():
std::set<int> s1, s2;
s1 = getAnExcitingSet();
transform(s1.begin(), s1.end(),
std::inserter(s2, s2.begin()), ExcitingUnaryFunctor());
The insert iterator will then call s2.insert(s2....