Insert content next to node in a tree

Question

I created a Binary Tree. This is my code:

\begin{tikzpicture}[level/.style={sibling distance=80mm/#1}]
\node[circle,draw](z){$50$}
    child {node [circle,draw] {$30$}
        child {node [circle,draw] {$10$}
            \cm
            child {node [circle,draw] {$20$}}}
        child {node [circle,draw] {$40$}}}
    child {node [circle,draw] {$80$}
        child {node [circle,draw] {$60$}
            \cm
            child{node [circle,draw] {$70$}}}
        child {node [circle,draw] {$90$}
            child{node [circle,draw] {$85$}}
            child{node [circle,draw] {$95$}}}};
\end{tikzpicture}

How can I add small numbers next to the nodes, like here?

Thank you.

Answer 1

I do not know the definition of \cm in your code, so I remove it. You can use label to place another node around original node. See pgfmanual sec 17.10.2 The Label Option.

\documentclass[tikz, border=1cm]{standalone}

\begin{document}
\begin{tikzpicture}[level/.style={sibling distance=80mm/#1}]
\node[circle,draw,label={[red]above:{1}}](z){$50$}
    child {node [circle,draw,label={[green]above left:{5}}] {$30$}
        child {node [circle,draw,label={[green]above left:{5}}] {$10$}
            child {node [circle,draw,label={[green]above left:{5}}] {$20$}}}
        child {node [circle,draw,label={[teal]right:{5}}] {$40$}}}
    child {node [circle,draw,label={[orange]above right:{6}}] {$80$}
        child {node [circle,draw,label={[green]above left:{5}}] {$60$}
            child{node [circle,draw,label={[green]above left:{5}}] {$70$}}}
        child {node [circle,draw,label={[draw,rotate=45,orange, anchor=west]above right:{test code}}] {$90$}
            child{node [circle,draw,label={[green]above left:{5}}] {$85$}}
            child{node [circle,draw,label={[green]right:{5}}] {$95$}}}};
\end{tikzpicture}
\end{document}