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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...
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.
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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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How do I delete NuGet packages that are not referenced by any project in my solution?
Somehow during the upgrade to VS2012 and .NET 4.5, I've managed to get NuGet confused. There are packages that appear in the package manager (and the packages folder) that I cannot delete (I believe they are legacy ASP.NET NuGet packages that have been replaced with new package names with the new v...
How can I test https connections with Django as easily as I can non-https connections using 'runserv
I have an application that uses "secure" cookies and want to test it's functionality without needing to set up a complicated SSL enabled development server. Is there any way to do this as simply as I can test non-encrypted requests using ./manage.py runserver ?
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Which is faster : if (bool) or if(int)?
The above topic made me do some experiments with bool and int in if condition. So just out of curiosity I wrote this program:
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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...