如何避免自动机节点漂移？

Question

我想绘制一个 NFA，并使其适合列宽，我将其设为锯齿形。令我沮丧的是，它看起来就像喝了很多杯龙舌兰酒后才离开酒吧。我曾尝试明确指定 q₇ – q₁₁ 的相对位置，但没有成功。这个额外的偏移来自哪里？我现在该如何将其拉直？

\documentclass[tikz,border=5pt]{standalone}
\usetikzlibrary{arrows,automata,positioning}
\usepackage{libertine}

\begin{document}
\begin{tikzpicture}[->,>=stealth',semithick,node distance=2cm,shorten >=5pt]
  \node[initial,state]      (0)                                     {q₀};
  \node[state]              (1)  [above right of=0]                 {q₁};
  \node[state]              (2)  [below of=1]                       {q₂};
  \node[state]              (3)  [above right of=2]                 {q₃};
  \node[state]              (4)  [below of=3]                       {q₄};
  \node[state]              (5)  [above right of=4]                 {q₅};
  \node[state]              (6)  [below of=5]                       {q₆};
  \node[state]              (7)  [above right=1cm and 1cm of 6]     {q₇};
  \node[state]              (8)  [below of=7]                       {q₈};
  \node[state]              (9)  [above right=1cm and 1cm of 8]     {q₉};
  \node[state]              (10) [below=1cm of 9]                   {q₁₀};
  \node[state]              (11) [above right=1cm and 1cm of 10]    {q₁₁};
  \node[state,accepting]    (12) [below=1cm of 11]                  {q₁₂};

  \path (0)     edge [right]                node {\textit{F}}       (1)
        (1)     edge [right]                node {\textit{o}}       (2)
        (2)     edge [right]                node {\textit{o}}       (3)
        (3)     edge [right]                node {\textit{:}}       (4)
        (4)     edge [right]                node {␣}                (5)
        (5)     edge [right]                node {\textit{t}}       (6)
        (6)     edge [right]                node {\textit{h}}       (7)
        (7)     edge [right]                node {\textit{i}}       (8)
        (8)     edge [right]                node {\textit{n}}       (9)
        (9)     edge [right]                node {\textit{g}}       (10)
        (10)    edge [right]                node {\textit{s}}       (11)
        (11)    edge [right]                node {\textit{!}}       (12)
        (0)     edge [loop above, above]    node {$Σ$}          (0)
  ;
\end{tikzpicture}
\end{document}

Answer 1

\foreach我认为您可以使用（自动化就是爱）和一些节点放置计算来节省大量代码空间。

该字符␣未在我的示例中显示，但我猜测对于在这种情况下解决方案的工作来说它并不重要。

输出

代码

\documentclass[margin=5pt]{standalone}
\usepackage{tikz}

\usetikzlibrary{arrows,automata}

\usepackage{libertine}

\begin{document}
\begin{tikzpicture}[->,>=stealth',semithick,node distance=2cm,shorten >=5pt]

\foreach \labels [count=\x starting from 0, remember=\x as \lastx (initially 0)] in {%
{$Σ$},
\textit{F},%
\textit{o},%
\textit{o},%
\textit{:},%
\textit{␣},%
\textit{t},%
\textit{h},%
\textit{i},%
\textit{n},%
\textit{g},%
\textit{s},%
\textit{!}%
}{
    \pgfmathsetmacro\xpos{int(\x+1-mod(\x+1,2))}
    \pgfmathsetmacro\ypos{int(mod(\x,2)*2)}
    \ifnum\x=0
        \node[initial,state] (\x) at (0,0) {$q_{\x}$};
        \path (0)  edge [loop above, above] node {\labels} (0);
    \else\ifnum\x=12
        \node[accepting,state] (\x) at (\xpos,\ypos) {$q_{\x}$};
    \else
        \node[state] (\x) at (\xpos,\ypos) {$q_{\x}$};
    \fi
        \path (\lastx) edge[right] node {\labels} (\x);
    \fi
}

\end{tikzpicture}
\end{document}