How to sort three variables using at most two swaps?

Question

The following algorithm can sort three variables x, y and z of type K which are comparable using operator<

Answer 1

Cool question :)

If assembly is available to you, and the values fit in a register, then you can probably do it extremely fast by just loading them into registers and doing a few compares, jumping to the right scenario to put the values back. Maybe your compiler makes this optimization already.

Either way, if performance is your goal, take a look at the generated machine code and optimize there. For such a small algorithm that's where you can squeeze performance out of.