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Explain how finding cycle start node in cycle linked list work?
...beginning of linked list while keeping the hare at meeting place, followed by moving both one step at a time make them meet at starting point of cycle?
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quick random row selection in Postgres
... need to first do a SELECT COUNT(*) to figure out the value of N.
Update (by Antony Hatchkins)
You must use floor here:
SELECT myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
Consider a table of 2 rows; random()*N generates 0 <= x < 2 and for example SELECT myid FROM mytable OFFSET 1....
How to replace all occurrences of a character in string?
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Unfortunately, this allows to replace only one char by another char. It cannot replace a char with more chars (that is, by a string). Is there a way to do a search-replace with more chars?
– SasQ
Aug 9 '12 at 9:26
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What is sharding and why is it important?
...r.
From Wikipedia:
Horizontal partitioning is a design principle whereby rows of a database table are held separately, rather than splitting by columns (as for normalization). Each partition forms part of a shard, which may in turn be located on a separate database server or physical location. ...
Error :Request header field Content-Type is not allowed by Access-Control-Allow-Headers
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As hinted at by this post Error in chrome: Content-Type is not allowed by Access-Control-Allow-Headers just add the additional header to your web.config like so...
<httpProtocol>
<customHeaders>
<add name="Access-...
What are copy elision and return value optimization?
... occurs - skip to this answer.
Copy elision is an optimization implemented by most compilers to prevent extra (potentially expensive) copies in certain situations. It makes returning by value or pass-by-value feasible in practice (restrictions apply).
It's the only form of optimization that elides (...
Select the values of one property on all objects of an array in PowerShell
...eInfo objects. You can always inspect the type coming through the pipeline by piping to Get-Member (alias gm).
ls | select -Property Name | gm
So, to expand the object to be that of the type of property you're looking at, you can do the following:
ls | select -ExpandProperty Name
In your case,...
Count work days between two dates
...ore robust but also more obscure solution is to replace the last two lines by: -(case datepart(dw, @StartDate)+@@datefirst when 8 then 1 else 0 end) -(case datepart(dw, @EndDate)+@@datefirst when 7 then 1 when 14 then 1 else 0 end)
– Torben Klein
Aug 20 '12 at ...
Debugging “Element is not clickable at point” error
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This is caused by following 3 types:
1.The element is not visible to click.
Use Actions or JavascriptExecutor for making it to click.
By Actions:
WebElement element = driver.findElement(By("element_path"));
Actions actions = new Action...
Difference between return and exit in Bash functions
...;
Causes a function to stop executing and return the value specified by n to its caller. If n is omitted, the return status is that of the last command executed in the function body.
... on exit [n]:
Cause the shell to exit with a status of n. If n is omitted, the exit status is ...