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if you want to know the number of bits constituting an integer look no further. Here is a very simple solution.

int get_number_of_bits(int the_number){
           int bits = 1;
           int div = (the_number/2);
           while(div != 0){
                      bits++;
                      div = div/2;
           }
           return bits;
}

So this is just a simple division by 2 loop, that counts the number of times we could divide the number by two without the result being less than 1 (which is the number of bits -1).

This works for positive integers from 0 and up.

Now if you wanted to know the number of bits required to represent a number of elements (i.e. you want to know how many bits would represent a number of states, elements or anything you like)

then use the same algorithm above, except that you need to change the line:  int div = the_number/2   into int div = (the_number-1)/2

this is because, number of states or elements is never 0.

Feedback is very welcome.