f

#### New Daily Quiz... OK, Not Really... I am looking for an optimized not-'in-place' 'quick select' algorthm/matlab script/c code

Hello All,

The 'quick select' algorithm finds the kth smallest element in the array wi=
thout doing a sort first (https://en.wikipedia.org/wiki/Quickselect ). With=
proper selection of the k value(s) it is one of the fastest algorithms to =
find the median.

I have spent considerable time trying to find a not-'in-place' 'quick selec=
t' algorithm. I have written my own version in MATLAB, but I am certain the=
re is an implementation 'out there' that is more optimized than what I have=
done (hopefully in C).

I found a reference to the not-'in-place' version being significantly faste=
r than the 'in-place' version, which makes sense because it eliminates a lo=
t of data swapping within the array at a cost of additional memory that is =
1X or 2X the size of the input array. Since I want to apply it to a fairly =
short array, having one or two additional arrays of the same length is not =
significant in terms of memory.

Does anyone know where to find an optimized not-'in-place' version of 'quic=
k select'?

Thanks,

Dirk Bell

 0
bellda2005
3/21/2016 9:54:47 PM
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