Obfuscated SWAP
Ken Johnson
ken at aiai.ed.ac.uk
Wed Aug 23 20:14:50 AEST 1989
Well, I tried it and it works, at least in the example I chose. This
code
main( )
{
int x, y;
x = 12;
y = 3;
x ^= y ^= x ^= y; /* Swap X and Y over */
printf("x = %d\ny = %d\n",x,y);
}
produces this output:
x = 3
y = 12
I don't understand how it works, but I do now understand why C
programmers have a reputation for going around showing each other bits
of paper and saying `I bet you can't guess what this does!'
-- Ken
--
Ken Johnson, AI Applications Institute, 80 South Bridge, Edinburgh EH1 1HN
E-mail ken at aiai.ed.ac.uk, phone 031-225 4464 extension 212
`I have read your article, Mr. Johnson, and I am no wiser than when I
started.' -- `Possibly not, sir, but far better informed.'
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