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Java HashMap performance optimization / alternative
...={99,100}) will hash to the same value as (a[]={3,1,2}, b[]={100,99}). Actually all keys k1 and k2 where sum(k1.a)==sum(k2.a) and sum(k1.b)=sum(k2.b) will result in collisions. I suggest assigning a weight to each position of the array:
hash = hash * 5381 + (c0*a[0] + c1*a[1]);
hash = hash * 5381 +...
How can I tell how many objects I've stored in an S3 bucket?
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There is no way, unless you
list them all in batches of 1000 (which can be slow and suck bandwidth - amazon seems to never compress the XML responses), or
log into your account on S3, and go Account - Usage. It seems the billing dept knows exactly how many object...
How to remove an item for a OR'd enum?
...amp; it with the ~ (complement) of 'BLUE'.
The complement operator essentially reverses or 'flips' all bits for the given data type. As such, if you use the AND operator (&) with some value (let's call that value 'X') and the complement of one or more set bits (let's call those bits Q and thei...
XPath contains(text(),'some string') doesn't work when used with node with more than one Text subnod
I have a small problem with Xpath contains with dom4j ...
6 Answers
6
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Undefined, unspecified and implementation-defined behavior
... coming from other languages (other languages try to hide it better). Basically, it is possible to write C++ programs that do not behave in a predictable way, even though many C++ compilers will not report any errors in the program!
Let's look at a classic example:
#include <iostream>
int ma...
HTML select form with option to enter custom value
...e input, with a value of the id of the datalist.
Update: As of March 2019 all major browsers (now including Safari 12.1 and iOS Safari 12.3) support datalist to the level needed for this functionality. See caniuse for detailed browser support.
It looks like this:
<input type="text" list="c...
How do you implement a “Did you mean”? [duplicate]
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Actually what Google does is very much non-trivial and also at first counter-intuitive. They don't do anything like check against a dictionary, but rather they make use of statistics to identify "similar" queries that returned mo...
What is code coverage and how do YOU measure it?
...ted by using a specialized tool to instrument the binaries to add tracing calls and run a full set of automated tests against the instrumented product. A good tool will give you not only the percentage of the code that is executed, but also will allow you to drill into the data and see exactly which...
Best Practices for Laravel 4 Helpers and Basic Functions?
...lean way: Create a library. That way it'll be autoloaded ONLY when you actually use it.
Create a libraries folder inside your app folder
Create your library file, create a class in it, and add static functions to it
Option 1: Edit start/global.php to add app_path().'/libraries' to the ClassLoader:...
How to remove files and directories quickly via terminal (bash shell) [closed]
... +1 and glad you added the "Be careful!" part... definitely a "Sawzall" command that can quickly turn a good day into a bad one.. if wielded carelessly.
– itsmatt
Apr 15 '10 at 1:30
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