Rcpp: continued fractions and precision

Question

I am struggling about floating points in Rcpp and how to get the numeric output from continued fractions in a numeric vector.

Here is my demo code:

library(Rcpp)
cppFunction('NumericVector signC() {
    NumericVector out1(3);
    out1[0]=round(0.888888888);
    out1[1]=round(1/3);
    out1[2]=1/3;
    return out1;
}')

The output from my demo code:

> signC()
[1] 1 0 0

I am wondering why 1/3 was convert to be 0 and how to get 0.3333333 from 1/3? The 1/3 was working fine under R environment.

Thanks, I appreciate any replies in advance!