Array MinMax Function Problem

[atreyucurses]

I have the question:
Write the definition of a function max that has three int parameters and returns the largest.


My attempt is does not work properly can anyone tell me why?

int max(int a, int b, int c)
{
if (num1 > num2 && num1 > num3)
{
return num1;
}
else if (num2 > num1 && num2 > num3)
{
return num2;
}
else if (num3 > num1 && num3 > num2)
{
return num3;
}
}

[firedraco]

You are passing 3 parameters (a, b, and c), but you are checking for variables called num1, num2, and num3.

[jsmith]

Challenge:

rewrite the above code to use only 3 boolean tests instead of 6.

[Computergeek01]

Isn't this really 9 Boolean tests? Since the '&&' operator is 'a*b=true\false'? :p Not trying to one up you just pointing out that this is even more inefficent then previously thought.

[sammy34]

I'm not sure if j's challenge was meant for all of us beginners, but I decided to give it a shot:

int GetLargest(int a, int b, int c)
{
	return (a>b) ?	// Is a greater than b?
		((a>c) ? a : c)	// Yes - but is a > c? If yes, return a, otherwise return c.
		: ((b>c) ? b : c); // No - hence b>=a. Is b > c? If yes, return b, otherwise return c.
}

3 boolean tests here, right?

[Computergeek01]

Maybe less?

if (a>b)
{
     if (a>c)
     { return a;}
                       }

if (b>c)
{return b;}

else
{return c;}

Yes technically there are three boolean operators, but your system only ever runs two comparisons before assuming that 'c' is the largest variable.

EDIT: Never mind this is what sammy34 did but he didn't point out that the system only runs to comparisons so I had to *ugh* read the code to see it :p.

[jsmith]

Bingo.

My way was:

    if( a > b && a > c )
        return a;

    if( b > c )
        return b;

    return c;

(Though Computergeek01, it will run all three if c > a > b.)

And you can one-liner it:

    return std::max( a, std::max( b, c ) );

This actually runs only 2 checks.