\begin{tikzpicture}[
    squarednode/.style={rectangle,  very thick, minimum size=5mm},
    yellownode/.style={rectangle, fill=yellow!30, very thick, minimum size=5mm},
    ]
    
    \draw[very thick] (0,0)--(1.5,0)--(1.5,0.5)--(1,0.5)--(1,1)--(0.5,1)--(0.5,1.5)--(0,1.5)--cycle;
    \draw[green, ultra thick, fill = green!30] (0,0)--(1.5,0)--(1.5,0.5)--(0.5,0.5)--(0.5,1.5)--(0,1.5)--cycle;
    \draw[fill=yellow!30] (0,0.5) rectangle (0.5,1);
    \node[squarednode] at (0.25,0.25) (int) {1};
    \node[squarednode] at (0.75,0.25) (int) {2};
    \node[squarednode] at (1.25,0.25) (int) {4};
    \node[squarednode] at (0.25,0.75) (int) {3};
    \node[squarednode] at (0.75,0.75) (int) {5};
    \node[squarednode] at (0.25,1.25) (int) {6};
    \draw[step=0.5,gray, very thin] (0,0) grid (2,2);
    \draw (0,2)--(2,0);
    
    
    
%    \node[squarednode] at (4.25,0.25) (int) {1};
%    \node[squarednode] at (4.75,0.25) (int) {2};
%    \node[squarednode] at (5.25,0.25) (int) {3};
%    \node[squarednode] at (5.75,0.25) (int) {5};
%    \node[squarednode] at (6.25,0.25) (int) {7};
%    \node[squarednode] at (4.25,0.75) (int) {4};
%    \node[squarednode] at (4.75,0.75) (int) {6};
%    \draw[step=0.5,gray, very thin] (4,0) grid (8,1.5);
%    \draw (4,1.5)--(8,0);
%    \draw[very thick] (4,0)--(6.5,0)--(6.5,0.5)--(5,0.5)--(5,1)--(4,1)--cycle;
    
    \end{tikzpicture}