Adjacency matrix in LaTex

adjacency.tex

\begin{wrapfigure}{r}{0.5\textwidth}
    \centering
    \caption{Adjacency List}
    \begin{tikzpicture}[>=stealth] 
        \matrix (M) [matrix of nodes,% 
            column sep=-\pgflinewidth,% 
            row sep=1mm,% 
            nodes in empty cells,
            nodes={draw, fill=gray!20,%
            minimum width=.5cm, outer sep=0pt,% 
            minimum height=.7cm, anchor=center}, 
            column 1/.style={nodes={minimum height=.8cm}}]%
        { 
            &[2mm] C & &[2mm] L & /  \\ 
            & I & & U & / \\ 
            & C & / \\ 
            & D & & U & / \\ 
            & F & & K & &[2mm] L & / \\ 
            & E & & D & / \\ 
            & F & / \\ 
            & G & & D & / \\ 
            & H & & J & & K & / \\ 
            & B & & G & / \\ 
            & B & & G & / \\         
            & A & & H & & J & / \\         
            & B & / \\ 
        }; 
        
        \foreach \v [count=\i] in {U,C,I,L,D,F,E,K,G,H,J,B,A} { 
            \path (M-\i-1) [late options={label=left:\v}]; 
            \draw[->] (M-\i-1)--(M-\i-2.west); 
        } 

        \foreach \i in {1,2,4,5,6,8,9,10,11,12} { 
            \draw[->] (M-\i-3.center)--(M-\i-4.west); 
        } 

        \foreach \i in {5,9,12} { 
            \draw[->] (M-\i-5.center)--(M-\i-6.west); 
        } 
    \label{fig:adjacency}
    \end{tikzpicture}
\end{wrapfigure}