added algodat questions

gsd-questions.tex

@@ -88,6 +88,39 @@ Musterloesung here
 
 \section{Algorithms and Data Structures}
 
+\subsection{In-situ List Reversal}
+Describe an algorithm to reverse a singly-linked list that \emph{does not}
+copy any memory cells.
+
+\ifdefined\loesung
+    {\bf Solution}: Maintain three pointers following each other: current, next, and
+    previous. The first pointer is one element ahead of the second. Reverse each pointer
+    as you you.
+\fi
+
+\subsection{Preorder Tree Traversal}
+Consider the following tree and state the \emph{preorder} and \emph{inorder} traversal.
+\begin{verbatim}
+     5
+   /   \
+  7     4
+   \   / \
+    1 2   9
+\end{verbatim}
+Which data structure do you need to implement such a traversal?
+\ifdefined\loesung
+    {\bf Solution}: Preorder: 5, 7, 1, 4, 2, 9; Inorder: 7, 1, 5, 2, 4, 9.
+    Such traversals are implemented using a stack (explicitly or implicitly using
+    a recursive traversal)
+\fi
+
+\subsection{Breadth-First-Search}
+What is the BFS traversal of the tree above? Which data structure is needed to implement
+such a traversal?
+\ifdefined\loesung
+    {\bf Solution}: BFS: 5, 7, 4, 1, 2, 9. You need a queue to implement BFS.
+\fi
+
 \section{Networking}
 
 \section{Regular Expressions and Shells}