<p>I tried "x = y ** e", but that didn't work.</p>

use the
```
pow
```
function (it takes
```
float
```
s/
```
double
```
s though).
```
man pow
```
:
```
```
#include <math.h>

   double pow(double x, double y);
   float powf(float x, float y);
   long double powl(long double x, long double y);
```
```
EDIT
: For the special case of positive integer powers of
```
2
```
, you can use bit shifting:
```
(1 << x)
```
will equal
```
2
```
to the power
```
x
```
. There are some potential gotchas with this, but generally, it would be correct.