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How can I multiply and divide using only bit shifting and adding?
...kes a constant multiple of time compared to addition and shifting. If I recall correctly, modern processors, if pipelined properly, can do multiplication just about as fast as addition, by messing with the utilization of the ALUs (arithmetic units) in the processor.
...
What is a method that can be used to increment letters?
...ded to expand it a bit beyond the scope of the original question to potentially help people who are stumbling on this from Google.
I find that what I often want is something that will generate sequential, unique strings in a certain character set (such as only using letters), so I've updated this a...
Read properties file outside JAR file
I have a JAR file where all my code is archived for running. I have to access a properties file which need to be changed/edited before each run. I want to keep the properties file in the same directory where the JAR file is. Is there anyway to tell Java to pick up the properties file from that direc...
subtle differences between JavaScript and Lua [closed]
...= operators are of lower precedence than >, >=, <, <=. In Lua, all comparison operators are the same precedence.
Lua supports tail calls.
UPDATE: JS now supports tail calls.
Lua supports assignment to a list of variables. While it isn't yet standard in Javascript, Mozilla's JS engine ...
C#: Assign same value to multiple variables in single statement
...nteresting to know that the get accessor of the intermediate value is not called. Only the set accessor is invoked for all property accessed in the assignation sequence.
Take for example a class that write to the console everytime the get and set accessor are invoked.
static void Main(string[] arg...
UTF-8 byte[] to String
... You can see in here the java.nio.charset.Charset.availableCharsets() map all the charsets not just the charsets in the StandardCharsets. And if you want to use some other charset and still want to prevent the String constructor from throwing UnsupportedEncodingException you may use java.nio.charse...
One SVN repository or many?
... its own tags, trunk and branches. If one gets too big or I need to physically isolate a customer's code for their comfort, I can quickly and easily create a new repository.
I recently consulted with a relatively large firm on migrating multiple source code control systems to Subversion. They have...
Understanding repr( ) function in Python
...gt;>> x
'foo'
So the name x is attached to 'foo' string. When you call for example repr(x) the interpreter puts 'foo' instead of x and then calls repr('foo').
>>> repr(x)
"'foo'"
>>> x.__repr__()
"'foo'"
repr actually calls a magic method __repr__ of x, which gives the s...
Best way to test if a row exists in a MySQL table
...RE ...)
and per the documentation, you can SELECT anything.
Traditionally, an EXISTS subquery starts with SELECT *, but it could
begin with SELECT 5 or SELECT column1 or anything at all. MySQL
ignores the SELECT list in such a subquery, so it makes no difference.
...
Is there a NumPy function to return the first index of something in an array?
...:
itemindex = numpy.where(array==item)
The result is a tuple with first all the row indices, then all the column indices.
For example, if an array is two dimensions and it contained your item at two locations then
array[itemindex[0][0]][itemindex[1][0]]
would be equal to your item and so woul...