Making AVL trees in Latex

Question

I'm completely new to latex and I'm currently trying to create a flow of inserting nodes into a tree. I'm having a problem with the lines on my trees as they become straight for some of them, does anyone know how to fix this?

\begin{minipage}{0.1\textwidth}
 \centering
\begin{tikzpicture}[
edge from parent path=
  {(\tikzparentnode.south) .. controls +(0,-.5) and +(0,.5)
                           .. (\tikzchildnode.north)},
every node/.style={draw,circle, label distance=-2mm},
level distance=20mm
]
\node [label=330:$0$]{5};
\end{tikzpicture}
\end{minipage}%
\begin{minipage}{0.02\textwidth}
  \centering
  $\rightarrow$
  \end{minipage}%
\begin{minipage}{0.1\textwidth}
   \centering
\begin{tikzpicture}[
      edge from parent path=
      {(\tikzparentnode.south) .. controls +(0,-.5) and +(0,.5)
                           .. (\tikzchildnode.north)},
every node/.style={draw,circle, label distance=-2mm},
level distance=20mm
]
\node [label=330:$1$]{5}
      child {node[label=330:$0$] {4}};
\end{tikzpicture}
\end{minipage}%

Welcome to TSE. Please post a Minimal Working Example, instead of a code snippet. — José Carlos Santos, May 30 '23 at 22:40
Use forest to draw these kinds of trees. See e.g. https://tex.stackexchange.com/a/252601/ (you don't need the fancy looking branches, but the basic structure is identical.) — Alan Munn, May 30 '23 at 23:45

Zarko · Accepted Answer · 2023-05-31T04:21:38.787

Edit:

An example of AVL tree (as presented in wikipedia):

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[
C/.style = {draw, circle, minimum size=1.5em, inner sep=0pt,
            label={[font=\scriptsize, text=blue, inner sep=0pt]330:$#1$}},
                   ]
\node [C=-1] {5}
    child {node[C=1] {5}}
    child {node[C=0] {4}}
    ;
\end{tikzpicture}
\end{document}

or as evolution of two trees drawn with pure \tikz and use positioning library (arrows.meta is only for nice looking arrows heads):

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                positioning}
\begin{document}
\begin{tikzpicture}[
node distance = 7mm and 21mm,
C/.style = {draw, circle, minimum size=1.5em, inner sep=0pt,
            label={[font=\scriptsize, text=blue, inner sep=0pt]330:$#1$}},
                   ]
\node (n1)[C=-1] {5};
    \node (n21) [C=1, above right=of n1] {5};
    \node (n22) [C=0, below right=of n1] {4};
\draw   (n21) -- (n22);
\draw[-Straight Barb,shorten <=7mm, shorten >=7mm]   (n1) -- (n1 -| n21);
\end{tikzpicture}
\end{document}

Making AVL trees in Latex

1 Answers1