Did you know you can swap the value of two variables without temp??
$a = $a + $b;
$b = $a – $b;
$a = $a – $b;
I wish I were so clever as to come up with that on my own. Still, I post it here to spark the imagination of those who find it as fascinating as I.
😉
I should point out that this post arose from a pasta gratin, the baking of which required a swap of two pans to different racks in the oven. Many thanks to Jeremy for englightening us on this subject.
🙂
If you worry about arithmetic overflow, XOR comes to the rescue
#include
main() {
int a =5;
int b=7;
a = a ^b;
b = b ^a;
a = a^ b;
printf (“%d %d\n”, a , b);
}
Neat, I can vaguely remember doing that once in a programming class two years ago. Now it will hopefully stay on my mind!
Oh, that’s cool! This:
($a, $b) = ($b, $a);
would also do the job (in Perl) and might be a bit more readable 🙂
That is cool… not sure if C++ compilers would keep the optimization in however – if you really need to cut the extra variable out it might be best to do it in assembly.
Am I ever glad to program in sane languages that can do swapping on one line, like Perl (but Python is much better).