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Is multiplication and division using shift operators in C actually faster?
... back, I benchmarked two
versions of my hashing algorithm:
unsigned
hash( char const* s )
{
unsigned h = 0;
while ( *s != '\0' ) {
h = 127 * h + (unsigned char)*s;
++ s;
}
return h;
}
and
unsigned
hash( char const* s )
{
unsigned h = 0;
while ( *s != '\0' ...
postgresql - sql - count of `true` values
...
SELECT COALESCE(sum(CASE WHEN myCol THEN 1 ELSE 0 END),0) FROM <table name>
or, as you found out for yourself:
SELECT count(CASE WHEN myCol THEN 1 END) FROM <table name>
...
How does this program work?
...oat is converted to double, as the prototype of printf is int printf(const char*, ...), from 6.5.2.2/7,
The ellipsis notation in a function prototype declarator causes argument type conversion to stop after the last declared parameter. The default argument promotions are performed on trailing ar...
Get list of databases from SQL Server
...
Execute:
SELECT name FROM master.sys.databases
This the preferred approach now, rather than dbo.sysdatabases, which has been deprecated for some time.
Execute this query:
SELECT name FROM master.dbo.sysdatabases
or if you pref...
Data binding to SelectedItem in a WPF Treeview
How can I retrieve the item that is selected in a WPF-treeview? I want to do this in XAML, because I want to bind it.
20 An...
What is the meaning of “POSIX”?
...cannot be used
. is cwd, .. parent
portable filenames
use at most max 14 chars and 256 for the full path
can only contain: a-zA-Z0-9._-
See also: what is posix compliance for filesystem?
Command line utility API conventions
Not mandatory, used by POSIX, but almost nowhere else, notably not in ...
Get filename and path from URI from mediastore
I have an onActivityResult returning from an mediastore image selection which I can get a URI for an image using the following:
...
Converting String to Int with Swift
...
Can i ask why i am getting an error when i omit the '?' char? Why do i need to state 'a' as an optional?
– Manos Serifios
Jun 2 '16 at 20:16
...
Prevent users from submitting a form by hitting Enter
...area>.
<input ... onkeydown="return event.key != 'Enter';">
<select ... onkeydown="return event.key != 'Enter';">
...
To reduce boilerplate, this is better to be done with jQuery:
$(document).on("keydown", ":input:not(textarea)", function(event) {
return event.key != "Enter";...
HTML input - name vs. id [duplicate]
...<form>, <iframe>, <img>, <map>, <input>, <select>, <textarea>
Name does not have to be unique, and can be used to group elements together such as radio buttons & checkboxes
Can not be referenced in URL, although as JavaScript and PHP can see the URL ther...