pow()
returns a double
, the implicit conversion from double
to int
is "rounding towards zero".
So it depends on the behavior of the pow()
function.
If it's perfect then no problem, the conversion is exact.
If not:
1) the result is slightly larger, then the conversion will round it down to the expected value.
2) if the result is slightly smaller, then the conversion will round down which is what you see.
solution:
Change the conversion to "round to nearest integer" by using rounding functions
c=lround(pow((5),(n)));
In this case, as long as pow()
has an error of less than +-0.5 you will get the expected result.