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Should I use a data.frame or a matrix?
...ter in the code of the function only new values were recorded into already allocated spaces, and there was no overhead of adding new rows to the DF. This makes the comparison even more fair, and it also made my job simpler as I did not need to rewrite anything further in the function. Just one line ...
Java: Detect duplicates in ArrayList?
... Would it be more efficient to tell the HashSet how much space to allocate: Set<T> set = new HashSet<T>(list.size());? Given a List parameter I think it is more efficient if it is common for the list to not contain duplicates.
– Paul Jackson
...
What is move semantics?
...start with a very simple string class which only holds a pointer to a heap-allocated block of memory:
#include <cstring>
#include <algorithm>
class string
{
char* data;
public:
string(const char* p)
{
size_t size = std::strlen(p) + 1;
data = new char[size]...
Why use iterators instead of array indices?
... end+1(!). For streams the iterator model is just surreal -- an imaginary token that does not exist. Likewise for linked lists. The paradigm only makes sense for arrays, and then not much. Why do I need two iterator object, not just one...
– Tuntable
Jan 21...
What is the use case of noop [:] in bash?
...causes bash to give a syntax error:
line 4: syntax error near unexpected token `fi'
line 4: `fi'
Bash can't have empty blocks (WTF). So you add a no-op:
if [ "$foo" != "1" ]
then
#echo Success
:
fi
or you can use the no-op to comment out the lines:
if [ "$foo" != "1" ]
then
: e...
If my interface must return Task what is the best way to have a no-operation implementation?
...
@Asad it reduces allocations (and with it GC time). Instead of allocation new memory and constructing a Task instance each time you need a completed Task, you only do this once.
– i3arnon
Aug 7 '15 at 9:...
Node.js setting up environment specific configs to be used with everyauth
...
Example: on my machine the .env file is this:
NODE_ENV=dev
TWITTER_AUTH_TOKEN=something-needed-for-api-calls
My local .env overrides any environment variables. But on the staging or production servers (maybe they're on heroku.com) the environment variables are pre-set to stage NODE_ENV=stage or...
mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to
...ion:
NOTE The mysql_ functions are deprecated and have been removed in php version 7.
Check $result before passing it to mysql_fetch_array. You'll find that it's false because the query failed. See the mysql_query documentation for possible return values and suggestions for how to deal with th...
Algorithm to randomly generate an aesthetically-pleasing color palette [closed]
...n in their web page.
http://tools.medialab.sciences-po.fr/iwanthue/index.php
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How can I parse JSON with C#?
...e(webClient.DownloadString("https://api.foursquare.com/v2/users/self?oauth_token=XXXXXXX"));
Console.WriteLine(result.response.user.firstName);
That last Console.WriteLine is pretty sweet...
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