Add marked tree figure

1 files changed, 21 insertions, 1 deletions

diff --git a/mgr.tex b/mgr.tex
index a89eb4b..61e5039 100644
--- a/mgr.tex
+++ b/mgr.tex
@@ -668,6 +668,24 @@ and $k$ will correspond to a marked node that's not on the path from $x$ to $y$
 (or some unmarked vertex if there were no marked vertices at all in the range we
 check).
 
+\begin{figure}
+    \centering
+    \def\svgwidth{0.5\columnwidth}
+    \input{tree-marked.pdf_tex}
+    \caption{
+        A preprocessed marked tree. The marked vertices are colored dark grey.
+        To the left of each vertex is its pre-order number. To the right is its
+        post-order number. On the bottom is the table $\prefixtable$ with only
+        the marked vertices' prefix numbers not replaced by $\infty$. The red
+        rectangle marks the range for which we issue an RMQ question when
+        answering a highest marked descendant question form the vertex with
+        post-order index 7 down to the one with post-order index 2.
+    }\label{marked-figure}
+\end{figure}
+
+See Figure \ref{marked-figure} for a visual example of the data structure
+described.
+
 \section{Answering branch infix regular questions}
 
 With the above problem solved, we are ready to finish our algorithm for branch
@@ -685,7 +703,9 @@ copy of $Q$ on the path towards the copy of $Q$ that contains $y$?''. To achieve
 this, we create a copy of $T$ in which we mark the vertices where an edge from a
 $c$-colored vertex points to a vertex with a lower color. This tree we
 preprocess for highest marked descendant on path questions, solved in the
-previous section.
+previous section. Note that Figure \ref{marked-figure} is exactly the marked
+tree we create and preprocess for the green color of the colored graph in Figure
+\ref{tree-figure}.
 
 Now question answering can proceed similar to the word case. Given a question
 ``does the word on vertices from $x$ down to $y$ belong to $L$?'', let $x'$ be