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Linq select objects in list where exists IN (A,B,C)
...ad of array for allowedStatus because HashSet's contains method is fastest and there'll be performance issues with array if it contains more than 1000 items. var allowedStatus = new HashSet<string> { "A", "B", "C" };
– Jay Shah
Nov 9 '18 at 18:14
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Negative weights using Dijkstra's Algorithm
I am trying to understand why Dijkstra's algorithm will not work with negative weights. Reading an example on Shortest Paths , I am trying to figure out the following scenario:
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Maximum filename length in NTFS (Windows XP and Windows Vista)?
...ndividual components of a filename (i.e. each subdirectory along the path, and the final filename) are limited to 255 characters, and the total path length is limited to approximately 32,000 characters.
However, on Windows, you can't exceed MAX_PATH value (259 characters for files, 248 for folders)...
Repeating characters in VIM insert mode
...this sequence works:
Ctrl+o 80i- Esc
Ctrl+o is used to issue normal commands without leaving INSERT mode,
80 the repetition,
i to insert,
- the character you want to insert,
Esc to leave INSERT mode.
Another one without EVER leaving INSERT mode:
Ctrl+o :norm 8ia Return
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Algorithm to calculate the number of divisors of a given number
...st of primes you'll need to see how many of those primes act as a divisor (and how often).
Here's some python for the algo Look here and search for "Subject: math - need divisors algorithm". Just count the number of items in the list instead of returning them however.
Here's a Dr. Math that explai...
Any reason not to use '+' to concatenate two strings?
...e Python interpreter has to create a new string object for each iteration, and it ends up taking quadratic time. (Recent versions of CPython can apparently optimize this in some cases, but other implementations can't, so programmers are discouraged from relying on this.) ''.join is the right way t...
Why are elementwise additions much faster in separate loops than in a combined loop?
Suppose a1 , b1 , c1 , and d1 point to heap memory and my numerical code has the following core loop.
10 Answers
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How to use Class in Java?
There's a good discussion of Generics and what they really do behind the scenes over at this question , so we all know that Vector<int[]> is a vector of integer arrays, and HashTable<String, Person> is a table of whose keys are strings and values Person s.
However, what stumps me ...
“unpacking” a tuple to call a matching function pointer
.... doesn't work from the signatures: your std::make_unique expects a tuple, and a tuple can be created from an unpacked tuple only via another call to std::make_tuple. This is what I've done in the lambda (although it's highly redundant, as you can also simply copy the tuple into the unique pointer w...
How to declare global variables in Android?
I am creating an application which requires login. I created the main and the login activity.
17 Answers
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