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Designing function f(f(n)) == -n
...turn n - 1
else:
return -1 * (n + 1)
Python automatically promotes integers to arbitrary length longs. In other languages the largest positive integer will overflow, so it will work for all integers except that one.
To make it work for real numbers you need to replace the n ...
How do I use cascade delete with SQL Server?
...o perform cascading delete in SQL Server when a record from T1 is deleted, all associated records in T2 also deleted.
8 An...
What are the differences between Abstract Factory and Factory design patterns?
...le the desired object
instantiation.
The quote assumes that an object is calling its own factory method here. Therefore the only thing that could change the return value would be a subclass.
The abstract factory is an object that has multiple factory methods on it. Looking at the first half of your...
How do I shutdown, restart, or log off Windows via a bat file?
... -l — Logs off.
shutdown -h — Hibernates.
Note: There is a common pitfall wherein users think -h means "help" (which it does for every other command-line program... except shutdown.exe, where it means "hibernate"). They then run shutdown -h and accidentally turn off their computers. Watch out f...
Node.js get file extension
... Try 'filename.css.gz'.split('.').slice(1).join('.') to get all extensions
– Trevor
Jul 31 '17 at 21:53
11
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How to debug heap corruption errors?
...nctionality was in Application Verifier.
Electric Fence (aka "efence"), dmalloc, valgrind, and so forth are all worth mentioning, but most of these are much easier to get running under *nix than Windows. Valgrind is ridiculously flexible: I've debugged large server software with many heap issues u...
Rearrange columns using cut
...
This is very often inefficient. Typically, you will find that the corresponding Awk script is a lot faster, for example. You should also be careful to quote the values "$col2" and "$col1" -- there could be shell metacharacters or other shenanigans in the data.
...
Difference between “git checkout ” and “git checkout -- ”
...his is not Git-specific, it's a general Unix command line convention. Normally you use it to clarify that an argument is a file name rather than an option, e.g.
rm -f # does nothing
rm -- -f # deletes a file named "-f"
git checkout1 also takes -- to mean that subsequent arguments are not ...
How to find out the number of CPUs using python
...sing Python. The result should be user/real as output by time(1) when called with an optimally scaling userspace-only program.
...
MVVM in WPF - How to alert ViewModel of changes in Model… or should I?
...
RaisePropertyChanged("ViewModelCopyOfSomeProperty");
}
But typically this is only needed if more than one object will be making changes to the Model's data, which is not usually the case.
If you ever have a case where you don't actually have a reference to your Model property to attach t...