% Compile with:
% htlatex Binary_Splitting.tex
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\def\pgfsysdriver{pgfsys-tex4ht.def}
\usepackage{tikz}
\usetikzlibrary{calc}
\usetikzlibrary{positioning}
\begin{document}
    \begin{tikzpicture}
      \begin{scope}
        [
            every node/.style={rectangle, draw, minimum height=1.4em},
            level distance=8mm,
            level 1/.style={nodes={minimum width=4cm}, sibling distance=48mm},
            level 2/.style={nodes={minimum width=2cm}, sibling distance=24mm},
            level 3/.style={nodes={minimum width=10mm}, sibling distance=12mm},
            edge from parent/.style={draw=none}
        ]
        \node[minimum width=8cm] (r) {}
          child { node {}
            child { node {}
              child { node (a) {\scriptsize{$C(N)$}} }
              child { node {} }}
            child { node {}
              child { node[fill=blue] (n) {} }
              child { node {} }}}
          child { node {}
            child { node {}
              child { node {} }
              child { node {} }}
            child { node {}
              child { node {\scriptsize{$C(1)$}} }
              child { node (z) {\scriptsize{$C(0)$}} }}};
      \end{scope}
      \node[below=1mm of n] {$O(\log N)$};
      \draw[<->]
        ($ (r.north east) + (0.5,0) $)
        -- node[right] (t) {$O(\log N)$}
        ($ (z.south east) + (0.5,0) $);
      \draw[<->]
        ($ (r.north west) + (0,0.3) $)
        -- node[above] {$O(N \log N)$}
        ($ (r.north east) + (0,0.3) $);
    \end{tikzpicture}
\end{document}