%\usetikzlibrary{positioning, shapes, calc}
\begin{figure}[ht]
%
    \begin{center}
    \scalebox{0.7}
	{
        \begin{tikzpicture}[node distance=4mm]
            % 定义节点样式
            \tikzset{
                stateWithBorder/.style={draw, circle, minimum width=8mm},
                stateWithoutBorder/.style={ draw=none, minimum width=8mm}
            }
        
            % Nodes
            \node[stateWithBorder] (0) {1};
            \node[stateWithBorder, right=of 0] (1) {2 };
            \node[stateWithBorder, right=of 1] (2) {3 };
            \node[stateWithoutBorder, right=of 2] (3) {...};
            \node[stateWithoutBorder, right=of 3,node distance=1mm] (4) {...};
            %\node[stateWithBorder, right=of 4] (5) {9};
            \node[stateWithBorder, right=of 4] (6) {10};
            \node[stateWithBorder, right=of 6] (7) {11};
            \node[stateWithBorder, right=of 7] (8) {12};
            \node[draw, rectangle, fill=gray!50, right=of 8] (DEAD) {T};

            \node[above=of 0.west, node distance=12mm] {start};

            \draw[solid,->] (0) -- (1);
            \draw[solid,->] (1) -- (2);
            \draw[solid,->] (2) -- (3);
            \draw[solid,->] (4) -- (6);
            %\draw[solid,->] (5) -- (6);
            \draw[solid,->] (6) -- (7);
            \draw[solid,->] (7) -- (8);
            \draw[solid,->] (8) -- (DEAD);
            \draw[solid,->] (0.north) to[out=60,in=120] (2.north west);
            \draw[solid,->] (1.north) to[out=60,in=120] ([yshift=2mm]3.north);
            \draw[solid,->] (2.north) to[out=60,in=120] ([yshift=2mm]4.north);
            \draw[solid,->] ([yshift=3mm]4.north west) to[out=60,in=120] (6.north west);
            \draw[solid,->] (4.north) to[out=60,in=120] (7.north west);
            \draw[solid,->] (6.north) to[out=60,in=120] (8.north west);
            \draw[solid,->] (7.north) to[out=60,in=120] (DEAD.north west);
            %\draw[solid,->] (8.south west) to[out=240,in=300] (0.south east);
            
        \end{tikzpicture}
        }
    \caption{Boyan Chain.}
        \label{boyanchain}
    \end{center}
\end{figure}