Find Fibonacci Numbers in O(n)

Problem:
Find Fibonacci Numbers in O(n) times.

Answer:

    // O(n), but n < 65536
    private int[] fib = new int[ 65536 ];
    public int fib2( int n ) {
        if ( n == 0 ) return 0;
        if ( n == 1 ) return 1;
        if ( fib[ n ] != 0 ) return fib[ n ];
        fib[ n ] = fib2( n - 1 ) + fib2( n - 2 );
        return fib[ n ];
    }