自动机：节点垂直居中

Question

如何使节点 1 和 6 垂直居中，如下图所示？谢谢。

\documentclass[12pt]{book}
\usepackage[paperwidth=16cm, paperheight=24cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}

\usepackage{qtree}
\usepackage{adjustbox}
\usepackage[activate={true,nocompatibility},final,tracking=true,kerning=true,spacing=true,factor=1100,stretch=10,shrink=10]{microtype}
\usepackage{multicol}

\usepackage{ragged2e}
\usepackage{makecell, tabularx}

\usepackage{xcolor}

\usepackage{pstricks}  %%
\usepackage{tikz}  %%

\usetikzlibrary{arrows,automata,matrix,positioning}

\newcolumntype{L}[1]{>{\RaggedRight}X} % new
\newcommand\code[1]{\texttt{#1}}
\newcolumntype{C}[1]{>{\centering\arraybackslash}p{#1}}

\setlength{\unitlength}{1cm}

\begin{document}

    \begin{tikzpicture}[>=stealth', shorten >=1pt, auto, node distance=1cm]
        \node[initial, state](1){1};
        \node[state](2)[above right=of 1]{2};
        \node[state](3)[right=of 2]{3};
        \node[state](4)[below=of 2]{4};
        \node[state](5)[right=of 4]{5};
        \node[state, accepting](6)[right=of 5]{6};

        \path[->] (1) edge node {$\epsilon$}   (2);
        \path[->] (2) edge node {a}   (3);
        \path[->] (1) edge node {$\epsilon$}   (4);
        \path[->] (4) edge node {b}   (5);
        \path[->] (3) edge node {$\epsilon$}   (6);
        \path[->] (5) edge node {$\epsilon$}   (6);
    \end{tikzpicture}
\end{document}

Answer 1

主要变化：

• 把节点4放在below right=of 1
• 把节点6放在above right=of 5

\documentclass[12pt]{book}
\usepackage[paperwidth=16cm, paperheight=24cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}

\usepackage{tikz}

\usetikzlibrary{arrows,automata,matrix,positioning}

\begin{document}
    \begin{tikzpicture}[>=stealth', shorten >=1pt, auto, node distance=1cm]
        \node[initial, state](1){1};
        \node[state] (2) [above right=of 1] {2};
        \node[state] (3) [right=of 2]       {3};
        \node[state] (4) [below right=of 1] {4};
        \node[state] (5) [right=of 4]       {5};
        \node[state, accepting] (6) [above right=of 5] {6};

        \path[->] (1) edge node {$\epsilon$}   (2);
        \path[->] (2) edge node {a}   (3);
        \path[->] (1) edge node {$\epsilon$}   (4);
        \path[->] (4) edge node {b}   (5);
        \path[->] (3) edge node {$\epsilon$}   (6);
        \path[->] (5) edge node {$\epsilon$}   (6);
    \end{tikzpicture}
\end{document}