Robert Sedgewick 是如何生成图形的？

Question

是的，我认为有一个非常类似的问题，但没有答案。他是如何生成此处概述的论文中的图形的 http://www.cs.princeton.edu/~rs/talks/LLRB/LLRB.pdf

尝试在 TeX 中执行此操作...似乎不可能。这需要多少代码？

更新：更具体。我不想能够生成 pdf 第 3 页和第 4 页中概述的树。

Answer 1

希望这能帮助你入门

\documentclass[border = 5pt, tikz]{standalone}

\usetikzlibrary{shapes}
\usetikzlibrary{positioning}
\definecolor{mred}{RGB}{178,26,52}

\begin{document}
\begin{tikzpicture}[
  font = \itshape,
  % 
  node/.style = {minimum width = 1em, draw = black, circle, line width
    = 0.5pt},
  % 
  subtree/.style = {regular polygon, regular polygon sides = 3,
    anchor = north, draw = black, line width = 0.5pt,
    align = center, rounded corners = 6ex, outer sep = 0pt, outer sep
    = 0pt, yshift = 3em, inner sep = 1pt, text
    = mred, minimum width = 10em},
  % 
  normal edge/.style = {edge from parent/.style = {black, very thick,
      draw}},
  % 
  emph edge/.style = {edge from parent/.style = {mred, line width = 3pt,
      draw}},
  % 
  level/.style = {sibling distance = 40mm/#1^0.2}
  ]

  % tree
  \node (a) [node]{$a$}
  child[normal edge] {node[subtree] {less \\ than a}}
  child[emph edge] {node[node] (b) {b}
    child[normal edge] {node[subtree] {between \\ a and b}}
    child[normal edge] {node[subtree] {greater \\ than b}}
  };
  % labels
  \node[left = 3em, mred] (lbl h) at (a.north west){h};
  \draw[->, mred] (lbl h) -- (a);

  \node[above = 2em] (a par) at (a.north){};
  \draw[] (a par) -- (a);

  \node[right = 3em, mred, align = center] (lbl spec) at (a par.north
  east){Could be right or left, \\ red or black};
  \draw[->, mred] (lbl spec) -- (a par);

  \node[right = 3em, mred] (lbl x) at (b.north east){\bf{x}};
  \draw[->, mred] (lbl x) -- (b);


\end{tikzpicture}
\end{document}