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Time complexity of Sieve of Eratosthenes algorithm
...oose upper-bound is n(1+1/2+1/3+1/4+1/5+1/6+…1/n) (sum of reciprocals of all numbers up to n), which is O(n log n): see Harmonic number. A more proper upper-bound is n(1/2 + 1/3 + 1/5 + 1/7 + …), that is sum of reciprocals of primes up to n, which is O(n log log n). (See here or here.)
The "find...
How to remove item from list in C#?
...== 2);
resultList.Remove(itemToRemove);
When you are not sure the item really exists you can use SingleOrDefault. SingleOrDefault will return null if there is no item (Single will throw an exception when it can't find the item). Both will throw when there is a duplicate value (two items with the s...
postgresql list and order tables by size
How can I list all the tables of a PostgreSQL database and order them by size ?
7 Answers
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Disable ONLY_FULL_GROUP_BY
I accidentally enabled ONLY_FULL_GROUP_BY mode like this:
26 Answers
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How do I grant myself admin access to a local SQL Server instance?
I installed SQL Server 2008 R2 to my local machine. But, I can't create a new database because of rights (or lack of).
6 An...
How do I pass variables and data from PHP to JavaScript?
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There are actually several approaches to do this. Some require more overhead than others, and some are considered better than others.
In no particular order:
Use AJAX to get the data you need from the server.
Echo the data into the page...
Determine if variable is defined in Python [duplicate]
...ime? This is not always obvious because (1) the variable could be conditionally set, and (2) the variable could be conditionally deleted. I'm looking for something like defined() in Perl or isset() in PHP or defined? in Ruby.
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How to select lines between two marker patterns which may occur multiple times with awk/sed
... @KasunSiyambalapitiya: Mostly it means I like to use it. Formally, it specifies that the next argument is (part of) the script that sed should execute. If you want or need to use several arguments to include the entire script, then you must use -e before each such argument; otherwise,...
Correct way to delete cookies server-side
...path=/; expires=Thu, 01 Jan 1970 00:00:00 GMT
Note that you cannot force all browsers to delete a cookie. The client can configure the browser in such a way that the cookie persists, even if it's expired. Setting the value as described above would solve this problem.
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How to REALLY show logs of renamed files with git?
...use the content as a whole has a meaningful history.
A file rename is a small special case of "content" moving between paths. You might have a function that moves between files which a git user might trackdown with "pickaxe" functionalitly (e.g. log -S).
Other "path" changes include combining and ...