Programming question! :)

[Fats]

Code: [Select]


int test(num)
{
  if (num<4185)return 4;
  if (num<4507)return 3;
  if (num<4883)return 2;
  if (num<5327)return 1;
  return 0;
}


If you don't want to do it in a function you could use ? : operator like:

Code: [Select]


  rank =
    (num<4185) ? 4 :
    (num<4507) ? 3 :
    (num<4883) ? 2 :
    (num<5327) ? 1 :
    0;


greets,
Staf.

[Fats]

Appologies! I only quickly looked over it If I had a larger array I would certainly investigate this method... I'm intrigued to see how a tiny microcontroller would cope with this kind of search!

OK, then you can go really funky. Using something like this:

Code: [Select]


struct lookup
{
   int num;
   unsigned char rank;
}

struct lookup vals[] =
{
    {4185, 4},
    {4507, 3},
    {4883, 2},
    {5327, 1},
    {MAX, 0}
}


If you make the array size a power of two you should be able to implement the binary search with bit manipulation using |= and <<. Or you can start somewhere in the middle of the array with an index that is power of two and see that you don't go over the highest index.

greets,
Staf.