soluzione_esercitazione_1.tex

% !TEX TS-program = lualatex
\documentclass{standalone}
\usepackage{tikz}
\usepackage{pgf}
\usepackage{pgfcore}
\usepackage{pgfplots}
\usepackage{amsmath}
\usepackage{amsfonts}
\usetikzlibrary{graphs,graphdrawing,calc}
\pgfplotsset{compat=1.18}
\begin{document}
\usegdlibrary{trees}

\tikz[tree layout, nodes={circle, thick}, inner sep=0.5pt]
    \node[green, draw, text=black] {$s_0$}
    child { node[draw] {$s_1$} edge from parent node[fill=white]{$5$}
        child { node[draw] {$s_3$} edge from parent node[fill=white]{$3$}
        child { node[ draw, text=black] {$s_2$} edge from parent node[fill=white]{$4$}}
        child { node[, draw, text=black] {$s_4$} edge from parent node[fill=white]{$4$}}
        child { node[, draw, text=black] {$s_5$} edge from parent node[fill=white]{$6$}}
    }
    child [missing]
    }
    child { node[green, draw, text=black] {$s_2$} edge from parent node[fill=white]{$3$}
        child { node[green, draw, text=black] {$s_4$} edge from parent node[fill=white]{$5$}
            child { node[draw] {$s_2$} edge from parent node[fill=white]{$5$}}
            child { node[draw] {$s_3$} edge from parent node[fill=white]{$4$}}
            child { node[green, draw, text=black] {$s_5$} edge from parent node[fill=white]{$3$}}
        } 
        child { node[draw] {$s_0$} edge from parent node[fill=white]{$5$}}
    }
    ;

\end{document}