答案1
你可以从这样的事情开始:
\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{positioning, automata}
\begin{document}
\begin{tikzpicture}
\node[state, minimum width=1cm] (a) {};
\node[state, minimum width=1cm, accepting by double, right=2cm of a] (b) {};
\draw (a.north)--++(90:3mm)--([yshift=10mm]a.east)--([yshift=10mm]b.west)--([yshift=3mm]b.north)--(b.north);
\draw (a.45)--(a.north-|a.east)--(b.north-|b.west)--(b.135);
\draw[->] (a.60)--++(60:3mm)--++(0:6mm) coordinate(aux);
\draw[->] (a.70)--++(70:4mm) coordinate(aux1)--(aux1-|aux);
\end{tikzpicture}
\end{document}