\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{graphs.standard}
\begin{document}
\begin{tikzpicture}
[level distance=10mm,
every node/.style={fill=blue!40,circle,inner sep=1pt},
level 1/.style={sibling distance=20mm,nodes={fill=blue!40}},
level 2/.style={sibling distance=10mm,nodes={fill=blue!40}},
level 3/.style={sibling distance=5mm,nodes={fill=blue!40}}]
\node {50}
child {node {40}
child {node {10}}
child {node {12}}
}
child {node {60}
child {node {19}
child {node {11}}
}
child {node {18}}
};
\end{tikzpicture}
\end{document}