\documentclass[crop,tikz]{standalone}
\input{common-headers}

\begin{document}

\newcommand{\common}{%
  \coordinate (ll) at (-0.5cm,-0.5cm);
  \coordinate (ur) at ( 3.5cm, 3.5cm);
  \draw[thick] (ll) rectangle (ur);
  \clip (ll)+(-0.1cm,-0.1cm) rectangle ([shift={(0.1cm,0.1cm)}]ur);
}

\begin{tikzpicture}[
  cell/.style={fill=black!60, inner sep=0cm,
    minimum width=1cm, minimum height=1cm}]
  \common
  \node[cell] at (0cm,1cm) {};
  \node[cell] at (1cm,1cm) {};
  \node[cell] at (1cm,3cm) {};
  \node[cell] at (2cm,1cm) {};
  \node[cell] at (2cm,2cm) {};
  \draw[xshift=0.5cm,yshift=0.5cm] (ll) grid (ur);
\end{tikzpicture}

\begin{tikzpicture}[
  cell/.style={fill=black!60, inner sep=0cm,
    minimum width=1cm, minimum height=1cm}]
  \common
  \node[cell] at (0cm,2cm) {};
  \node[cell] at (1cm,0cm) {};
  \node[cell] at (1cm,1cm) {};
  \node[cell] at (2cm,1cm) {};
  \node[cell] at (2cm,2cm) {};
  \draw[xshift=0.5cm,yshift=0.5cm] (ll) grid (ur);
\end{tikzpicture}

\begin{tikzpicture}[
  cell/.style={fill=black!60, inner sep=0cm,
    minimum width=1cm, minimum height=1cm}]
  \common
  \node[cell] at (0cm,1cm) {};
  \node[cell] at (1cm,0cm) {};
  \node[cell] at (2cm,0cm) {};
  \node[cell] at (2cm,1cm) {};
  \node[cell] at (2cm,2cm) {};
  \draw[xshift=0.5cm,yshift=0.5cm] (ll) grid (ur);
\end{tikzpicture}

\begin{tikzpicture}[
  cell/.style={fill=black!60, inner sep=0cm,
    minimum width=1cm, minimum height=1cm}]
  \common
  \node[cell] at (1cm,0cm) {};
  \node[cell] at (1cm,2cm) {};
  \node[cell] at (2cm,0cm) {};
  \node[cell] at (2cm,1cm) {};
  \node[cell] at (3cm,1cm) {};
  \draw[xshift=0.5cm,yshift=0.5cm] (ll) grid (ur);
\end{tikzpicture}

\begin{tikzpicture}[
  cell/.style={fill=black!60, inner sep=0cm,
    minimum width=1cm, minimum height=1cm}]
  \common
  \node[cell] at (1cm,0cm) {};
  \node[cell] at (2cm,0cm) {};
  \node[cell] at (2cm,2cm) {};
  \node[cell] at (3cm,0cm) {};
  \node[cell] at (3cm,1cm) {};
  \draw[xshift=0.5cm,yshift=0.5cm] (ll) grid (ur);
\end{tikzpicture}



\end{document}