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What is dynamic programming? [closed]
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Dynamic programming is when you use past knowledge to make solving a future problem easier.
A good example is solving the Fibonacci sequence for n=1,000,002.
This will be a very long process, but what if I give you the results for n=1,000,000 and n=1,000,001? Sudde...
Python strptime() and timezones?
... noting this has been updated as of version 3.2 and the same documentation now also states the following:
When the %z directive is provided to the strptime() method, an aware datetime object will be produced. The tzinfo of the result will be set to a timezone instance.
Note that this doesn't w...
JSF backing bean structure (best practices)
...say -- 15 EL functions digging into that object from the JSF page, you are now tied not only to the bean, but to that object. Therefore it will be difficult to remove that object without breaking the UI.
– Zack Marrapese
Apr 16 '09 at 13:55
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Set every cell in matrix to 0 if that row or column contains a 0
...in the size of the matrix.
I use 1rst column and first row as markers to know where are rows/cols with only 1's. Then, there are 2 variables l and c to remember if 1rst row/column are all 1's also.
So the first pass sets the markers and resets the rest to 0's.
The second pass sets 1 in places wher...
Difference between natural join and inner join
... is the least-important aspect of a natural join. The things you need to know are (A) it automatically joins on fields of the same name and (B) it will f*** up your s*** when you least expect it. In my world, using a natural join is grounds for dismissal.
– user565869
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Proper practice for subclassing UIView?
...rarchy has been unarchived and initialized.
From the doc of NSNibAwaking (now superseded by the doc of awakeFromNib):
Messages to other objects can be sent safely from within awakeFromNib—by which time it’s assured that all the objects are unarchived and initialized (though not necessarily ...
How do you write a migration to rename an ActiveRecord model and its table in Rails?
...y.
Edit:
In Rails 3.1 & 4, ActiveRecord::Migration::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rename_table :old_table_name, :new_table_name
end
end
(You still have to go t...
PyPy — How can it possibly beat CPython?
...omment under that post, you will see that the writer of that post doesn't know link-time optimization. With link-time optimization enabled, the C code runs faster.
– Ali
Jun 26 '14 at 9:33
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How to copy an object in Objective-C
...lways with reference types, there are two notions of "copy". I'm sure you know them, but for completeness.
A bitwise copy. In this, we just copy the memory bit for bit - this is what NSCopyObject does. Nearly always, it's not what you want. Objects have internal state, other objects, etc, and ofte...
SQL Server: Filter output of sp_who2
... sp
JOIN master.dbo.sysdatabases sd ON sp.dbid = sd.dbid
ORDER BY spid
Now you can easily add any ORDER BY or WHERE clauses you like to get meaningful output.
Alternatively, you might consider using Activity Monitor in SSMS (Ctrl + Alt + A) as well
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