Solution (source code)

= Solution

Define the extended transition recursively by
$$
\widehat\Delta(q,\varepsilon)=\{q\},
\qquad
\widehat\Delta(q,wa)
=\bigcup_{p\in\widehat\Delta(q,w)}\Delta(p,a).
$$
The automaton accepts $w$ precisely when
$$
\boxed{w\in\mathcal L(N)
\quad\Longleftrightarrow\quad
\widehat\Delta(q_0,w)\cap F\ne\varnothing.}
$$