\sectionnn{Cha\^ines et cycles eul\'eriens}

\exercice[style=A,N=2,verif]{Les maisons}

Est-il possible de se promener dans chacune de ces maisons en passant une seule et une seule fois par chacune de ses ouvertures ?

\medskip

\begin{minipage}{.5\textwidth}
\begin{center}
\begin{tikzpicture}
\draw (0,0) rectangle +(6,4);
\draw (0,2) -- (6,2);
\draw (2,0) -- (2,2);
\draw (4,0) -- (4,2);
\draw (3,2) -- (3,4);
\fill[white] (1.9,.75) rectangle+(.2,.5);
\fill[white] (3.9,.75) rectangle+(.2,.5);
\fill[white] (2.9,2.75) rectangle+(.2,.5);
\fill[white] (.75,1.9) rectangle+(.5,.2);
\fill[white] (4.75,1.9) rectangle+(.5,.2);
\fill[white] (2.25,1.9) rectangle+(.5,.2);
\fill[white] (3.25,1.9) rectangle+(.5,.2);
\node[gray] at (1,1) {\Large A};
\node[gray] at (3,1) {\Large B};
\node[gray] at (5,1) {\Large C};
\node[gray] at (1.5,3) {\Large E};
\node[gray] at (4.5,3) {\Large D};
\end{tikzpicture}

Maison 1
\end{center}
\end{minipage}
\begin{minipage}{.5\textwidth}
\begin{center}
\begin{tikzpicture}
\draw (0,0) rectangle +(6,4);
\draw (0,2) -- (6,2);
\draw (2,0) -- (2,2);
\draw (4,0) -- (4,2);
\draw (3,2) -- (3,4);
\fill[white] (1.9,.75) rectangle+(.2,.5);
\fill[white] (3.9,.75) rectangle+(.2,.5);
\fill[white] (2.9,2.75) rectangle+(.2,.5);
\fill[white] (.75,1.9) rectangle+(.5,.2);
\fill[white] (4.75,1.9) rectangle+(.5,.2);
\fill[white] (2.25,1.9) rectangle+(.5,.2);
\fill[white] (3.25,1.9) rectangle+(.5,.2);
\fill[white] (1.25,3.9) rectangle+(.5,.2);
\fill[white] (4.25,3.9) rectangle+(.5,.2);
\fill[white] (.75,-.1) rectangle+(.5,.2);
\fill[white] (2.75,-.1) rectangle+(.5,.2);
\fill[white] (4.75,-.1) rectangle+(.5,.2);
\fill[white] (-.1,.75) rectangle+(.2,.5);
\fill[white] (-.1,2.75) rectangle+(.2,.5);
\fill[white] (5.9,.75) rectangle+(.2,.5);
\fill[white] (5.9,2.75) rectangle+(.2,.5);
\node[gray] at (1,1) {\Large A};
\node[gray] at (3,1) {\Large B};
\node[gray] at (5,1) {\Large C};
\node[gray] at (1.5,3) {\Large E};
\node[gray] at (4.5,3) {\Large D};
\end{tikzpicture}

Maison 2
\end{center}
\end{minipage}