Best way we know search for an integer
A very simple solution if your integers are not too big, let's say biggest integer is $U-1$ and there are $U$ different integers (between 0 and $U-1$), is to build a table T (bit matrix) of size $U$ with all bits set to $0$. Upon occurrence of item $k$ set $T(k)\leftarrow 1$.

If you want to search for an item $k$ you simply check if $T(k)$ is $1$ or $0$.
This solution takes $\Theta(U)$ space and $\Theta(1)$ time per inserted item, or per search.
If $U$ is much less than $n$ and you don't make deletions then I think
this solution is ideal in your case. If you make deletions of $U &gt; n$ then more sophisticated solutions are needed