Ecco una soluzione “spartana” (ma tikz permette qualità grafiche di altissimo livello) del codice, con la figura catturata dal pdf.
`
% ——– eucl.tex (Set.12)———–
% Esempio minimale del pacchetto tikz
%————————————
\documentclass{minimal}
\usepackage{tikz}
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[set style={{help lines}+=[dashed]}]
\draw[style=help lines] (0,0) grid +(12,12);
\draw (4,11) grid +(1,1);
\draw (6,10) grid +(1,1);
\draw (10,10) grid +(1,1);
%—–
\draw (4,9) grid +(1,1);
\draw (0,9) grid +(1,1);
%—–
\draw (6,8) grid +(1,1);
\draw (4,7) grid +(1,1);
\draw (6,6) grid +(1,1);
\draw (4,5) grid +(1,1);
%——————————————————
% red1
\draw [red,very thick,->] (5,11) — (6,10.5);
\draw [red,thick, ->] (7,10.5) — (8,10.5);
\draw (8.5,10.5) circle (0.5);
\draw [red,thick, ->] (9,10.5) — (10,10.5);
% blue1
\draw [blue,very thick,->] (6,10) — (5,9.5);
\draw [blue,thick,->] (4,9.5) — (3,9.5);
\draw (2.5,9.5) circle (0.5);
\draw [blue,thick,->] (2,9.5) — (1,9.5);
% ……… e così via
% ——– Fill numbers ———–
\node at (4.5,11.5) {2993};
\node at (6.5,10.5) {1095};
\node at (8.5,10.5) {2};
\node at (10.5,10.5) {2190};
%—
\node at (4.5,9.5) {803};
\node at (2.5,9.5) {1};
\node at (0.5,9.5) {803};
%—
\node at (3.5,8.5) {$da\; completare$};
\end{tikzpicture}
\end{document}
`
[attachment=425]scr13.png[/attachment]