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What is the difference between declarative and imperative programming? [closed]
I have been searching the web looking for a definition for declarative and imperative programming that would shed some light for me. However, the language used at some of the resources that I have found is daunting - for instance at Wikipedia .
Does anyone have a real-world example that they could ...
Why doesn't Dijkstra's algorithm work for negative weight edges?
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Recall that in Dijkstra's algorithm, once a vertex is marked as "closed" (and out of the open set) - the algorithm found the shortest path to it, and will never have to develop this node again - it assumes the path developed to this path is the shortest.
But with negative weights - it might not be...
How to “perfectly” override a dict?
..._contains__
# free setdefault, __eq__, and so on
import pickle
# works too since we just use a normal dict
assert pickle.loads(pickle.dumps(s)) == s
I wouldn't subclass dict (or other builtins) directly. It often makes no sense, because what you actually want t...
Difference between modes a, a+, w, w+, and r+ in built-in open function?
...tion, what is the exact difference between the modes w , a , w+ , a+ , and r+ ?
6 Answers
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How do I update an entity using spring-data-jpa?
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Identity of entities is defined by their primary keys. Since firstname and lastname are not parts of the primary key, you cannot tell JPA to treat Users with the same firstnames and lastnames as equal if they have different userIds.
So, if you want to update a User identified by its firstname a...
NHibernate vs LINQ to SQL
...orld projects I wonder if anyone knows how these two complement each other and how much their functionalities overlap?
9 An...
When should we use intern method of String on String literals
...in String pool, otherwise a new string object will be added in String pool and the reference of this String is returned.
1...
When to use references vs. pointers
I understand the syntax and general semantics of pointers versus references, but how should I decide when it is more-or-less appropriate to use references or pointers in an API?
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Array.Copy vs Buffer.BlockCopy
Array.Copy and Buffer.BlockCopy both do the same thing, but BlockCopy is aimed at fast byte-level primitive array copying, whereas Copy is the general-purpose implementation. My question is - under what circumstances should you use BlockCopy ? Should you use it at any time when you are copyi...
Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?
I've been profiling some of our core math on an Intel Core Duo, and while looking at various approaches to square root I've noticed something odd: using the SSE scalar operations, it is faster to take a reciprocal square root and multiply it to get the sqrt, than it is to use the native sqrt opcode!...