
diff -r ea39bbc8d98d -r 9755af1d74df cws/main_cw04.tex
--- a/cws/main_cw04.tex	Fri Nov 05 16:47:55 2021 +0000
+++ b/cws/main_cw04.tex	Fri Nov 05 17:20:01 2021 +0000
@@ -19,7 +19,7 @@
 
 \mbox{}\\[-18mm]\mbox{}
 
-\section*{Preliminary and Main Part 4 (Scala, 4 + 6 Marks)}
+\section*{Main Part 4 (Scala, 9 Marks)}
 
 \mbox{}\hfill\textit{``The problem with object-oriented languages is they’ve got all this implicit,}\\
 \mbox{}\hfill\textit{environment that they carry around with them. You wanted a banana but}\\
@@ -29,11 +29,14 @@
 \noindent
 This part is about searching and backtracking. You are asked to
 implement Scala programs that solve various versions of the
-\textit{Knight's Tour Problem} on a chessboard. The preliminary part (4\%) is
-due on  \sout{\cwNINE{}} \textcolor{red}{16 December} at 5pm; the core part (6\%) is due on \cwNINEa{} at 5pm.
-Any 1\% you achieve in the preliminary part counts as your ``weekly engagement''.
+\textit{Knight's Tour Problem} on a chessboard.
+% The preliminary part (4\%) is due on  \sout{\cwNINE{}}
+% \textcolor{red}{16 December} at 5pm; the core part (6\%)
+% is due on \cwNINEa{} at 5pm. Any 1\% you achieve in the
+% preliminary part counts as your ``weekly engagement''.
 \bigskip 
-%Note the core, more advanced, part might include material you have not
+
+% Note the core, more advanced, part might include material you have not
 %yet seen in the first three lectures. \bigskip
 
 \IMPORTANTNONE{}
@@ -164,9 +167,9 @@
 
 \subsection*{Reference Implementation}
 
-\mbox{}\alert{}\textcolor{red}{You need to download \texttt{knight1.jar} from KEATS. The one
-supplied with github does not contain the correct code. See Scala coursework
-section on KEATS.}\medskip
+%\mbox{}\alert{}\textcolor{red}{You need to download \texttt{knight1.jar} from K%EATS. The one
+%supplied with github does not contain the correct code. See Scala coursework
+%section on KEATS.}\medskip
 
 \noindent
 This Scala part comes with three reference implementations in form of
@@ -174,17 +177,17 @@
 computer. For example you can call Scala on the command line with the
 option \texttt{-cp knight1.jar} and then query any function from the
 \texttt{knight1.scala} template file. As usual you have to
-prefix the calls with \texttt{CW9a}, \texttt{CW9b} and \texttt{CW9c}.
+prefix the calls with \texttt{M4a}, \texttt{M4b} and \texttt{M4c}.
 Since some of the calls are time sensitive, I included some timing
 information. For example
 
 \begin{lstlisting}[language={},numbers=none,basicstyle=\ttfamily\small]
 $ scala -cp knight1.jar
-scala> CW9a.enum_tours(5, List((0, 0))).length
+scala> M4a.enum_tours(5, List((0, 0))).length
 Time needed: 1.722 secs.
 res0: Int = 304
 
-scala> CW9a.print_board(8, CW9a.first_tour(8, List((0, 0))).get)
+scala> M4a.print_board(8, M4a.first_tour(8, List((0, 0))).get)
 Time needed: 15.411 secs.
 
  51  46  55  44  53   4  21  12 
@@ -201,18 +204,15 @@
 \subsection*{Hints}
 
 \noindent
-\textbf{Preliminary Part} useful list functions: \texttt{.contains(..)} checks
+Useful list functions: \texttt{.contains(..)} checks
 whether an element is in a list, \texttt{.flatten} turns a list of
 lists into just a list, \texttt{\_::\_} puts an element on the head of
 the list, \texttt{.head} gives you the first element of a list (make
 sure the list is not \texttt{Nil}); a useful option function:
 \texttt{.isDefined} returns true, if an option is \texttt{Some(..)};
 anonymous functions can be constructed using \texttt{(x:Int) => ...},
-this function takes an \texttt{Int} as an argument.\medskip
-
-
-\noindent
-\textbf{Main Part} a useful list function: \texttt{.sortBy} sorts a list
+this function takes an \texttt{Int} as an argument; 
+a useful list function: \texttt{.sortBy} sorts a list
 according to a component given by the function; a function can be
 tested to be tail-recursive by annotation \texttt{@tailrec}, which is
 made available by importing \texttt{scala.annotation.tailrec}.\medskip
@@ -220,7 +220,7 @@
 
 
 
-\subsection*{Preliminary Part (4 Marks)}
+\subsection*{Tasks}
 
 You are asked to implement the knight's tour problem such that the
 dimension of the board can be changed.  Therefore most functions will
@@ -254,7 +254,7 @@
 knight moves (see above for the rules).
 
 
-\subsubsection*{Tasks (file knight1.scala)}
+\subsubsection*{Task 1 (file knight1.scala)}
 
 
 
@@ -294,9 +294,9 @@
   called with a path containing a single position---the starting field.
   They are expected to extend this path so as to find all tours starting
   from the given position.\\
-  \mbox{}\hfill[2 Marks]
+  \mbox{}\hfill[1 Mark]
 \end{itemize}
-
+  
 \noindent \textbf{Test data:} For the marking, the functions in (3)
 will be called with board sizes up to $5 \times 5$. If you search
 for tours on a $5 \times 5$ board starting only from field $(0, 0)$,
@@ -307,18 +307,6 @@
   $6\times 6$, $7\times 7$ and $8\times 8$ are 6637920, 165575218320,
   19591828170979904, respectively.}\smallskip
 
-
-\subsection*{Core Part (6 Marks)}
-
-
-\subsubsection*{Tasks (file knight1.scala cont.)}
-
-\mbox{}\alert{}\textcolor{red}{You need to copy your \texttt{knight1.scala}
-  from the preliminary part to the main part and then solve Tasks 4 and 5
-  inside the copied file. Do not forget to ``git add'' the file for
-  pushing the results to the directory \texttt{main4}.}\medskip
-
-
 \begin{itemize}
 \item[(4)] Implement a \texttt{first}-function. This function takes a list of
   positions and a function $f$ as arguments; $f$ is the name we give to
@@ -353,7 +341,7 @@
   \texttt{first}-function from (4), and searches recursively for single tour.
   As there might not be such a tour at all, the \texttt{first\_tour} function
   needs to return a value of type
-  \texttt{Option[Path]}.\\\mbox{}\hfill[1 Mark]
+  \texttt{Option[Path]}.\\\mbox{}\hfill[1 Mark]  
 \end{itemize}
 
 \noindent
@@ -362,6 +350,7 @@
 \bigskip
 
 %%\newpage
+\subsubsection*{Task 2 (file knight2.scala)}
 
 \noindent
 As you should have seen in the earlier parts, a naive search for tours beyond
@@ -396,8 +385,6 @@
 order.  When calculating the number of onward moves for each field, we
 do not count moves that revisit any field already visited.
 
-\subsubsection*{Tasks (file knight2.scala)}
-
 \begin{itemize}
 \item[(6)] Write a function \texttt{ordered\_moves} that calculates a list of
   onward moves like in (2) but orders them according to 
@@ -423,7 +410,7 @@
   \mbox{}\hfill[1 Mark]
 \end{itemize}    
 
-\subsubsection*{Task (file knight3.scala)}
+\subsubsection*{Task 3 (file knight3.scala)}
 \begin{itemize}
 \item[(9)] Implement a function \texttt{tour\_on\_mega\_board} which is
   the same function as in (8), \textbf{but} should be able to
@@ -443,7 +430,7 @@
   \begin{lstlisting}[language={},numbers=none,basicstyle=\ttfamily\small]
 $ scala -cp knight3.jar
   
-scala> CW9c.tour_on_mega_board(70, List((0, 0)))
+scala> M4c.tour_on_mega_board(70, List((0, 0)))
 Time needed: 9.484 secs.
 ...<<long_list>>...
 \end{lstlisting}%$




