03-05-1995
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                 ³quicksort for HP48 gx/sx/g/s ³
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this is a very fast ml prog to sort an array of real numbers.
there are 2 progs:
- qsort :  recieves array or list of real numbers and produces a sorted
           array of the numbers.
           if this routine gets a list then it converts it to an array
           and that sorts.
           if it gets an array then it NEWOB it and then sort.

- qshort : recieves only an array of reals and sorts it without NEWOBing
           it. it means that every var that refernce it will be changed and
           also other stack levels which are DUPed of it.
           the big adventage is that it doesn't need the extra memory for
           NEWObing it.

note that qshort is only a subset of qsort so choose what you like.

the sort routine works by the quicksort algorithm which is recursive and
its complexity is  O(N*logN) !.
recursion is a problem in HP48 since it has fixed 8 level return stack
so the program allocated memory for its own stack.
this means that if you sort a 16Kbyte array then you will need 10Kbyte free
to sort it (62.5% of the array).

however the prog is very fast. it can sort an array of 1200 reals in less
then 3 secs ( HP48G 's internal sort routine takes few minutes ).

this program was done as a practice of ML programming on the 48 and was tested
only on HP48GX-P (also it should work on all vertions). the prog is FREEWARE.
but I'm not liable to any dammage that can/would happen so use this prog on
your own responsebility.

if there are bugs I will be glad to hear and fix them.

     Tamir Demri
     email :   s2543671@techst02.technion.ac.il