I want to make a comment on the following url on this forum.
http://groups.google.com/group/comp....3c48178ecd3dd6
The comment revolves around the following the solution to a permute
problem posted by Lew:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void rotate(unsigned length, char *string)
{
char save;
save = *string;
while(--length)
{
*string=*(string+1);
++string;
}
*string = save;
}
void permute(unsigned length, char *string, unsigned depth)
{
if (length == 0)
printf("%s\n",string-depth);
else
{
unsigned count;
for (count = length ; count 0; --count)
{
permute(length-1,string+1,depth+1);
rotate(length,string);
}
}
}
int main(int argc, char **argv)
{
while (--argc)
{
char *source = malloc(strlen(*++argv)+1);
if (source)
{
strcpy(source,*argv);
printf("\nPermuting \"%s\"\n",source);
permute(strlen(source),source,0);
free(source);
}
}
return EXIT_SUCCESS;
}
I'll admit, the first time I saw this, I didn't have a clue what was
going on. Even after stepping through the code via the gnu debugger, I
had no clue. It was during my darkest hour that I discovered the
significance of backtrace and the difference between step-in and
step-out on my debugger. I'll have to admit, that was quite the
experience.
So Lew, or anyone else here. Do you have any more quality lines of c
code that you wish to share with us?
Chad
