Question

If I have five variables

int a,b,c,d,e;

What is the most efficient way to make sure they are all unique?

if(a!=b && a!=c && a!=d && a!=e && b!=c && b!=d && b!=e && c!=d && c!=e && d!=e)
{ 
   //Is this the most efficient way??
}

Answer 1

That pretty much is the most efficient way. It’s not necessarily the best looking code I’ve seen but it’ll work just fine. Any other solution involving data structures or functions is unlikely to be faster.

I’d recode it for beauty though:

if (a != b && a != c && a != d && a != e
           && b != c && b != d && b != e
                     && c != d && c != e
                               && d != e
) { 
    // Blah blah blah
}

Not necessarily exactly like that, just something a bit easier on the eyes when reading.