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Finding ALL duplicate rows, including “elements with smaller subscripts”
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You need to assemble the set of duplicated values, apply unique, and then test with %in%. As always, a sample problem will make this process come alive.
> vec <- c("a", "b", "c","c","c")
> vec[ duplicated(vec)]
[1] "c" "c"
> unique(vec[ ...
How to determine the version of the C++ standard used by the compiler?
...rup C++0x FAQ:
__cplusplus
In C++0x the macro __cplusplus will be set to a value that differs
from (is greater than) the current 199711L.
Although this isn't as helpful as one would like. gcc (apparently for nearly 10 years) had this value set to 1, ruling out one major compiler, until ...
Maximum number of characters using keystrokes A, Ctrl+A, Ctrl+C and Ctrl+V
This is an interview question from google. I am not able to solve it by myself. Can somebody shed some light?
14 Answers
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What does the slash mean in help() output?
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Why is processing a sorted array faster than processing an unsorted array?
...u stop the train to ask the driver which direction they want. And then you set the switch appropriately.
Trains are heavy and have a lot of inertia. So they take forever to start up and slow down.
Is there a better way? You guess which direction the train will go!
If you guessed right, it continues...
Best practices for SQL varchar column length [closed]
Every time is set up a new SQL table or add a new varchar column to an existing table, I am wondering one thing: what is the best value for the length .
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Mercurial — revert back to old version and continue from there
I'm using Mercurial locally for a project (it's the only repo there's no pushing/pulling to/from anywhere else).
7 Answers
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Retrieve filename from file descriptor in C
Is it possible to get the filename of a file descriptor (Linux) in C?
7 Answers
7
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Vim: What's the difference between let and set?
What's the difference between let and set in the vim editor?
5 Answers
5
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Read binary file as string in Ruby
I need an easy way to take a tar file and convert it into a string (and vice versa). Is there a way to do this in Ruby? My best attempt was this:
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