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# qsort descending order

 P: n/a In the ISO document http://www.open-std.org/jtc1/sc22/wg...docs/n1124.pdf in the detail of the qsort library function in 7.20.5.2, the description says that, the contents of the array are sorted into ascending order. MY QUESTION: Does it mean to include descending order also ? If not, suppose we write the comparison function in such a way that it returns less than, equal to, or greater than zero if the first argument is greater than, equal to, or less than the second argument, we should be able to use the qsort to sort the array elements into descending order. Am I correct or wrong ? Kindly explain. Mar 19 '07 #1
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 P: n/a su**************@yahoo.com, India said: In the ISO document http://www.open-std.org/jtc1/sc22/wg...docs/n1124.pdf in the detail of the qsort library function in 7.20.5.2, the description says that, the contents of the array are sorted into ascending order. MY QUESTION: Does it mean to include descending order also ? No. You define what "ascending" means in your comparison function, by the way in which you associate the return value of the function with the result of the comparison. If not, suppose we write the comparison function in such a way that it returns less than, equal to, or greater than zero if the first argument is greater than, equal to, or less than the second argument, we should be able to use the qsort to sort the array elements into descending order. Right. -- Richard Heathfield "Usenet is a strange place" - dmr 29/7/1999 http://www.cpax.org.uk email: rjh at the above domain, - www. Mar 19 '07 #2

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 P: n/a "osmium"

 P: n/a In article <45****************@news.xs4all.nl>, Richard Bos I think the word "ascending" should not have been used in thespecification. >Why not? Because, apparently, it is confusing. Of course you can say that 3,2,1 are in ascending order with respect to a comparison function that says 1>2>3, but is it the clearest way to do it? The only problem is finding a better terminology - perhaps the terms "earlier" and "later" could have been used? -- Richard -- "Consideration shall be given to the need for as many as 32 characters in some alphabets" - X3.4, 1963. Mar 19 '07 #5

 P: n/a "su**************@yahoo.com, India" wrote: > In the ISO document http://www.open-std.org/jtc1/sc22/wg...docs/n1124.pdf in the detail of the qsort library function in 7.20.5.2, the description says that, the contents of the array are sorted into ascending order. MY QUESTION: Does it mean to include descending order also ? If not, suppose we write the comparison function in such a way that it returns less than, equal to, or greater than zero if the first argument is greater than, equal to, or less than the second argument, we should be able to use the qsort to sort the array elements into descending order. Am I correct or wrong ? Kindly explain. The only thing that defines order is the comparison function. So you are correct. -- "A man who is right every time is not likely to do very much." -- Francis Crick, co-discover of DNA "There is nothing more amazing than stupidity in action." -- Thomas Matthews -- Posted via a free Usenet account from http://www.teranews.com Mar 20 '07 #6

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