Powers of two

Can't you use the math class pow function?

pow(number, power);

let say someone input 8,

i need to give the answer 3...

ah so you do logs..

Unfortunately the problem is because the log function returns a double number, and double numbers can't be stored 100 percent accurately.

You will probably get some invalid result because of this.

Try using the "ceil, and floor" functions to help you get the correct answer.

You actually could just just try using sprintf

like this:

double result = <log calculation>;

here is an example of only printing only 1 decimal
printf("%8.1d" result);  <-- creates a entire width of 8, and only 1 decimal space.

You can read up on this stuff.

here is a link I found:
http://cermics.enpc.fr/~ts/C/FUNCTIONS/format.html

correction:

printf("%8.1d" result);  
--> should be printf("%8.1d", result);

thanks...

it works with ceil..can i assume it is correct or do i need to check for floor ??

thanks

>> to get the power of two of the input,

If the input will be an integer value, this is relatively easy, since you have binary operators.

I agree; I think I probably should have mentioned using bitwise operators, but I wasn't 100 percent clear on if he would be doing this approach only for powers of 2....

Have a look up on "Binary bitwise operators"

Operators: ">>" and "<<" are quite helpful