Re: sorting in C
* echo dev [EMAIL PROTECTED] [020614 00:06] wrote: I am pooling in as many different ways of sorting data in C i can anyone have a fav??? If anyone can give me some ideas on the best way to sort data in C would be helpful.. Thanks man qsort -- -Alfred Perlstein [[EMAIL PROTECTED]] To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
echo dev wrote: I am pooling in as many different ways of sorting data in C i can anyone have a fav??? If anyone can give me some ideas on the best way to sort data in C would be helpful.. Thanks The Art Of Computer Programming Volume 3: Sorting and Searching Donald Knuth Addison-Wesley ISBN: 0-201-03803-X Knuth's books: Collect them all! Be the first on your block! -- Terry To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
Thus spake echo dev [EMAIL PROTECTED]: I am pooling in as many different ways of sorting data in C i can anyone have a fav??? If anyone can give me some ideas on the best way to sort data in C would be helpful.. Thanks I've always been partial to bogosort. To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
On Fri, 14 Jun 2002, David Schultz wrote: Thus spake echo dev [EMAIL PROTECTED]: I am pooling in as many different ways of sorting data in C i can anyone have a fav??? If anyone can give me some ideas on the best way to sort data in C would be helpful.. Thanks I've always been partial to bogosort. Hey, don't be _that_ mean to a poor Hotmail user -- maybe he got that address before W2K, layers of Local Director and Passport. OTOH, asking things like that here still deserves some mockery... -- Alex To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
On Fri, Jun 14, 2002 at 07:06:06AM +, echo dev wrote:
I am pooling in as many different ways of sorting data in C i can anyone
have a fav??? If anyone can give me some ideas on the best way to sort data
in C would be helpful.. Thanks
Below is an example of how to use qsort. Hope it helps.
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include stdio.h
#include stdlib.h
#include time.h
#define NUM_INTS 15
void print_array(int *array)
{
int i;
for (i = 0; i NUM_INTS; i++) {
printf(%d , array[i]);
}
putc('\n', stdout);
}
int comp(int *a, int *b)
{
return (*a - *b);
}
void gen_rand(int *array)
{
int i;
srand(time(NULL));
for (i = 0; i NUM_INTS; i++) {
array[i] = rand() % 99;
}
}
int main(void)
{
int array[NUM_INTS];
gen_rand(array);
print_array(array);
qsort(array, NUM_INTS, sizeof(*array),
(int (*)(const void *, const void *)) comp);
print_array(array);
putc('\n', stdout);
return 0;
}
--
L1: khromy ;khromy(at)lnuxlab.ath.cx
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Re: sorting in C
dumb question: extra in the previous post? why do both this qsort(array, NUM_INTS, sizeof(*array), (int (*)(const void *, const void *)) comp); and this qsort(array, NUM_INTS, sizeof(*array), (int (*)(const void *, const void *)) comp); work properly? I tried both and both compile/run/sort fine. (the difference afaik is that the first passes an *int[] aka int** and the second passes an int[] aka int*) -dan (noob) To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
* Dan Arlow [EMAIL PROTECTED] [2002-06-14 14:40 -0400]: dumb question: extra in the previous post? why do both this qsort(array, NUM_INTS, sizeof(*array), (int (*)(const void *, const void *)) comp); and this qsort(array, NUM_INTS, sizeof(*array), (int (*)(const void *, const void *)) comp); work properly? I tried both and both compile/run/sort fine. (the difference afaik is that the first passes an *int[] aka int** and the second passes an int[] aka int*) No, see http://www.eskimo.com/~scs/C-faq/q6.12.html Nicolas To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
On Friday 14 June 2002 06:36 pm, Nicolas Rachinsky wrote: | * Dan Arlow [EMAIL PROTECTED] [2002-06-14 14:40 -0400]: | dumb question: extra in the previous post? | | why do both this | | qsort(array, NUM_INTS, sizeof(*array), | (int (*)(const void *, const void *)) comp); | | and this |qsort(array, NUM_INTS, sizeof(*array), |(int (*)(const void *, const void *)) comp); | | work properly? I tried both and both compile/run/sort fine. | | (the difference afaik is that the first passes an *int[] aka int** and | the second passes an int[] aka int*) | | No, see http://www.eskimo.com/~scs/C-faq/q6.12.html I think that probably doesn't clarify much. (Indeed, in this case, it would seem to obfuscate the above question more than clarify since the question is why are they the same and the FAQ question is meant to explain why these two are *different* to somebody who expects them to be the *same.*) It's because an array *is* a pointer to the first element, and array is a pointer to the array, but the first element has the same address as the array, since the address of the array is the address of the first element. Thus, the code works as long as the compiler will accept it. If qsort had a typed first element, then you'd get an error message from one or the other of them (though it would probably work), but as it happens, qsort declares the type to be void *, so it will take *any* pointer type. Thus, no complaint from the compiler. | | Nicolas | | To Unsubscribe: send mail to [EMAIL PROTECTED] | with unsubscribe freebsd-hackers in the body of the message -- Brian T. Schellenberger . . . . . . . [EMAIL PROTECTED] (work) Brian, the man from Babble-On . . . . [EMAIL PROTECTED] (personal) http://www.babbleon.org http://www.eff.org http://www.programming-freedom.org If you smell the smoke you don't need to be told what you've got to do; Yet there's a certain breed, so very in-between, they'd rather take a vote. -- DEVO -- Here To Go To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
Re: sorting in C
On Fri, Jun 14, 2002 at 07:06:06AM +, echo dev wrote: I am pooling in as many different ways of sorting data in C i can anyone have a fav??? If anyone can give me some ideas on the best way to sort data in C would be helpful.. Thanks is that references helping you ? qsort(3), bsearch(3), hsearch(3), lsearch(3), db(3). Cyrille. -- Cyrille Lefevre mailto:[EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with unsubscribe freebsd-hackers in the body of the message
