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Image comparison - fast algorithm
...are any new images against that to determine if the new image is an exact (or close) duplicate of the base.
9 Answers
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Why is address zero used for the null pointer?
In C (or C++ for that matter), pointers are special if they have the value zero: I am adviced to set pointers to zero after freeing their memory, because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use ...
When to use PNG or JPG in iPhone development?
...CPU energy to display. However, large PNGs may take longer to read from storage than more compressed image formats, and thus be slower to display.
JPG's are smaller to store, but lossy (amount depends on compression level), and to display them requires a much more complicated decoding algorithm. ...
What is the equivalent of the C# 'var' keyword in Java?
One use of the var keyword in C# is implicit type declaration. What is the Java equivalent syntax for var ?
15 Answers
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#import using angle brackets < > and quote marks “ ”
...'m wondering what decides whether you're allowed to use <Header.h> or "Header.h" when you're importing files in Objective-C. So far my observation has been that you use the quote marks "" for files in your project that you've got the implementation source to, and angle brackets <>...
Is using a lot of static methods a bad thing?
...a class when that class doesn't require to keep track of internal states. For example, if I need to transform A into B and don't rely on some internal state C that may vary, I create a static transform. If there is an internal state C that I want to be able to adjust, then I add a constructor to set...
What is more efficient: Dictionary TryGetValue or ContainsKey+Item?
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This is more subtle: if(dict.ContainsKey(ikey)) dict[ikey]++; else dict.Add(ikey, 0);. But i think that TryGetValue is still more efficient since the get and set of the indexer property is used, isn't it?
– Tim...
Does Python have a string 'contains' substring method?
I'm looking for a string.contains or string.indexof method in Python.
10 Answers
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What are the pros and cons of performing calculations in sql vs. in your application
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It depends on a lot of factors - but most crucially:
complexity of calculations (prefer doing complex crunching on an app-server, since that scales out; rather than a db server, which scales up)
volume of data (if you need to access/aggregate a lot o...
What does WISC (stack) mean? [closed]
LAMP is a well-known acronym for the software/technology bundle/stack representing Linux , Apache , MySQL , PHP . There are a few passing references on the Web that use the acronym WISC to speak of the other (supposedly Microsoft-centric) software/technology bundle/stack in contrast to LAMP...