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need help in sorting

there is a property in the book saying:
block sorting on P processors using butcher's sort with merging
comparators can sort N records in a bout (Log p)2/ 2 parallell sort.
and i have question depinding in this property asking how many parellel
steps would be required to sort 100,000 records using 32 processors?

my answer was (log32) = (1.5)2 = 2.26/2 =1.132
1.132 *100000= 113273.8
is what am doing correct? is it areasonable answer?
thank you

Nov 25 '06 #1
1 1360

"zoro" <om********@nos pam.yahoo.comwr ote in message
news:e5******** *************** *******@localho st.talkaboutpro gramming.com...
there is a property in the book saying:
block sorting on P processors using butcher's sort with merging
comparators can sort N records in a bout (Log p)2/ 2 parallell sort.
and i have question depinding in this property asking how many parellel
steps would be required to sort 100,000 records using 32 processors?

my answer was (log32) = (1.5)2 = 2.26/2 =1.132
1.132 *100000= 113273.8
is what am doing correct? is it areasonable answer?
thank you
Your math is reasonably correct, but since I don't know which "THE BOOK"
you're using, it's not really possible to know how the figure was
determined, nor could I know what you're looking for. Since you didn't
supply the units, I can only guess it represents sorts. I can guess what a
butcher's sort is, but "merging comparators" can be implemented many ways
and may be considered a sort operation too. In essence, your answer could
be reasonable, but it is implementation dependent.

-NM

Nov 26 '06 #2

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