Re: problem on medians

ak said:

what are the least no. of comparisons to find the medain of a set of
n integers ?

I presume you mean "median".

The answer is of course 0, which occurs when n is 0, 1, or 2. For n = 0,
there is nothing to compare, so no comparisons can occur. When n is 1,
there is only one value, which is its own median, so no comparison is
required. When n is 2, the median is given by the sum of the two
elements divided by 2, and again no comparison is required.

It is also possible, albeit a little harder, to find the median in zero
comparisons when n > 2 provided only that the values are all members of
some simple arithmetic series, in any order but without any gaps and
with the highest and lowest members known.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
.

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