Lehrmaterialien und erste Beispielprogramme 3.5.2018

20180503/2-3-4-tree-1.cpp

+#include <iostream>
+
+template <typename element>
+class tree
+{
+
+  struct leaf
+  {
+    element *content[3];
+    leaf *child[4];
+  };
+
+  leaf *root;
+
+public:
+
+  tree ()
+  {
+    root = NULL;
+  }
+
+};
+
+int main ()
+{
+  tree <int> t;
+  return 0;
+}

20180503/2-3-4-tree-2.cpp

+#include <iostream>
+
+using namespace std;
+
+template <typename TElement>
+class TTree
+{
+
+  struct TEntry
+  {
+    TElement Content;
+    bool empty;
+
+    TEntry ()
+    {
+      empty = true;
+    }
+  };
+
+  struct TLeaf
+  {
+    TEntry Entry[3];
+    TLeaf *Leaf[4];
+  };
+
+  TLeaf *Root;
+
+public:
+
+  TTree ()
+  {
+    Root = NULL;
+  }
+
+  void Insert (TElement e)
+  {
+    if (!Root)
+      Root = new TLeaf ();
+    Root->Entry[0].Content = e;
+  }
+
+  void Print ()
+  {
+    for (int i = 0; i < 3; i++)
+      cout << Root->Entry[i].Content << " ";
+    cout << endl;
+  }
+
+};
+
+int main ()
+{
+  TTree <int> t;
+  t.Insert (42);
+  t.Print ();
+  return 0;
+}

20180503/2-3-4-tree-3.cpp

+#include <iostream>
+
+using namespace std;
+
+template <typename TElement>
+class TTree
+{
+
+  struct TEntry
+  {
+    TElement Content;
+    bool empty;
+
+    TEntry ()
+    {
+      empty = true;
+    }
+  };
+
+  struct TLeaf
+  {
+    TEntry Entry[3];
+    TLeaf *Leaf[4];
+  };
+
+  TLeaf *Root;
+
+public:
+
+  TTree ()
+  {
+    Root = NULL;
+  }
+
+  void Insert (TElement e)
+  {
+    if (!Root)
+      Root = new TLeaf ();
+    int i = 0;
+    while (i < 3 && !Root->Entry[i].empty)
+      i++;
+    if (i < 3)
+      Root->Entry[i].Content = e;
+  }
+
+  void Print ()
+  {
+    for (int i = 0; i < 3; i++)
+      cout << Root->Entry[i].Content << " ";
+    cout << endl;
+  }
+
+};
+
+int main ()
+{
+  TTree <int> t;
+  t.Insert (42);
+  t.Insert (13);
+  t.Insert (137);
+  t.Print ();
+  return 0;
+}

20180503/2-3-4-tree-4.cpp

+#include <iostream>
+
+using namespace std;
+
+template <typename TElement>
+class TTree
+{
+
+  struct TEntry
+  {
+    TElement Content;
+    bool empty;
+
+    TEntry ()
+    {
+      empty = true;
+    }
+  };
+
+  struct TLeaf
+  {
+    TEntry Entry[3];
+    TLeaf *Leaf[4];
+
+    TLeaf ()
+    {
+      for (int i = 0; i < 4; i++)
+        Leaf[i] = NULL;
+    }
+
+    void SetEntry (int i, TElement e)
+    {
+      Entry[i].Content = e;
+      Entry[i].empty = false;
+    }
+  };
+
+  TLeaf *Root;
+
+public:
+
+  TTree ()
+  {
+    Root = NULL;
+  }
+
+  void Insert (TElement e)
+  {
+    if (!Root)
+      Root = new TLeaf ();
+    int i = 0;
+    while (i < 3 && !Root->Entry[i].empty)
+      i++;
+    if (i < 3)
+      Root->SetEntry (i, e);
+  }
+
+  void Print ()
+  {
+    for (int i = 0; i < 3; i++)
+      cout << Root->Entry[i].Content << " ";
+    cout << endl;
+  }
+
+};
+
+int main ()
+{
+  TTree <int> t;
+  t.Insert (42);
+  t.Insert (13);
+  t.Insert (137);
+  t.Print ();
+  return 0;
+}

20180503/Zeichen_123.pdf

+../common/Zeichen_123.pdf
\ No newline at end of file

20180503/ad-20180503.tex

+% ad-20180503.pdf - Lecture Slides on Algorithms and Data Structures in C/C++
+% Copyright (C) 2018  Peter Gerwinski
+%
+% This document is free software: you can redistribute it and/or
+% modify it either under the terms of the Creative Commons
+% Attribution-ShareAlike 3.0 License, or under the terms of the
+% GNU General Public License as published by the Free Software
+% Foundation, either version 3 of the License, or (at your option)
+% any later version.
+%
+% This document is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this document.  If not, see <http://www.gnu.org/licenses/>.
+%
+% You should have received a copy of the Creative Commons
+% Attribution-ShareAlike 3.0 Unported License along with this
+% document.  If not, see <http://creativecommons.org/licenses/>.
+
+% README: Einführung in C++, Objekte
+
+\documentclass[10pt,t]{beamer}
+
+\usepackage{pgslides}
+\usepackage{tikz}
+\usepackage{soul}
+
+\newcommand{\underconstruction}{%
+  \begin{picture}(0,0)
+    \color{black}
+    \put(7,-2.2){\makebox(0,0)[b]{\includegraphics[width=1.5cm]{Zeichen_123.pdf}}}
+    \put(7,-2.5){\makebox(0,0)[t]{\shortstack{Änderungen\\vorbehalten}}}
+  \end{picture}}
+
+\title{Algorithmen und Datenstrukturen in C/C++}
+\author{Prof.\ Dr.\ rer.\ nat.\ Peter Gerwinski}
+\date{3.\ Mai 2018}
+
+\begin{document}
+
+\maketitleframe
+
+\nosectionnonumber{\inserttitle}
+
+\begin{frame}
+
+  \shownosectionnonumber
+
+  \begin{itemize}
+    \item[\textbf{1}] \textbf{Einführung}
+      \underconstruction
+      \hfill\makebox(0,0)[br]{\raisebox{2.25ex}{\url{https://gitlab.cvh-server.de/pgerwinski/ad.git}}}
+    \item[\textbf{2}] \textbf{Einführung in C++}
+    \item[\textbf{3}] \textbf{Datenorganisation}
+      \begin{itemize}
+        \item[3.1] Standard-Container-Templates
+        \item[3.2] Iteratoren
+        \color{medgreen}
+        \item[3.3] Hash-Tabellen
+        \item[3.4] Balancierte Bäume
+        \color{red}
+        \item[3.5] Intelligente Zeiger
+      \end{itemize}
+    \item[\textbf{4}] \textbf{Datenkodierung}
+%      \begin{itemize}
+%        \item Fehlererkennung und -korrektur
+%        \item Kompression
+%        \item Kryptographie
+%      \end{itemize}
+    \item[\textbf{5}] \textbf{Hardwarenahe Algorithmen}
+%      \begin{itemize}
+%        \item FFT, CORDIC, \dots
+%      \end{itemize}
+    \item[\textbf{6}] \textbf{Optimierung}
+%      \begin{itemize}
+%        \item Wegfindung, \dots
+%      \end{itemize}
+    \color{gray}
+    \item[\textbf{7}] \textbf{Numerik}
+  \end{itemize}
+
+\end{frame}
+
+\setcounter{section}{2}
+\section{Datenorganisation}
+
+\setcounter{subsection}{2}
+\subsection{Hash-Tabellen}
+
+\begin{frame}[fragile]
+  \showsection
+  \showsubsection
+
+  Idee: Ein String ist auch nur eine große Zahl.\\
+  Wenn man die irgendwie zurechtstutzt,\\
+  kann man sie als Array-Index verwenden.
+
+  \bigskip
+
+  \textbf{Übungsaufgabe:}
+
+  \smallskip
+
+  Schreiben Sie ein Programm, das zu Strings (z.\,B.\ Namen)\\
+  Datensätze speichern und diese in $\mathcal{O}(1)$ wieder abrufen kann.
+  \begin{itemize}
+    \item[(a)]
+      Verwenden Sie das Hash-Tabellen-Template\\
+      aus der C++-Standardbibliothek.
+    \item[(b)]
+      Programmieren Sie die Hash-Tabelle selbst.
+  \end{itemize}
+
+  \smallskip
+
+  Teamarbeit, Internet-Recherchen\\
+  und die Verwendung anderer Container-Standard-Templates\\
+  sind ausdrücklich erlaubt.
+\end{frame}
+
+\subsection{Balancierte Bäume}
+
+\begin{frame}[fragile]
+  \showsection
+  \showsubsection
+
+  \begin{itemize}
+    \item
+      \textbf{Problem:} Entartung von Bäumen\\
+      \textbf{Lösung:} variable Anzahl von Verzweigungen
+    \item
+      \textbf{Problem:} Datenstruktur zu groß für Hauptspeicher\\
+      \textbf{Lösung:} ``intelligentes'' Auslagern
+  \end{itemize}
+
+  \textbf{B-Baum:}
+  \begin{itemize}
+    \item
+      immer mindestens $t$, höchstens $2t$ Verzweigungen
+    \item
+      Einfügen: wenn Knoten voll, teilen
+    \item
+      Löschen:
+      \begin{itemize}\itemsep2pt
+        \item
+          unterste Ebene: ggf.\ verschieben, ggf.\ verschmelzen
+        \item
+          in inneren Knoten: Wert von unten ersetzen,
+          ggf.\ verschmelzen
+      \end{itemize}
+    \item
+      einfachster Fall: 2-3-4-Baum
+  \end{itemize}
+
+  \textbf{Übungsaufgabe}: Implementieren Sie einen 2-3-4-Baum\\
+  mit Methoden zum Suchen, Einfügen und Löschen
+
+\end{frame}
+
+\subsection{Intelligente Zeiger}
+
+\begin{frame}[fragile]
+  \showsection
+  \showsubsection
+
+  \textbf{Warum?}
+  \begin{itemize}
+    \item
+      bereits freigegebene Zeiger werden u.\,U.\ weiterhin verwendet
+    \item
+      Speicherlecks
+    \item
+      uninitialisierte Zeiger
+  \end{itemize}
+
+  \medskip
+
+  \begin{itemize}
+    \item
+      \lstinline{shared_ptr}
+    \item
+      \lstinline{weak_ptr}
+    \item
+      \lstinline{unique_ptr}
+    \item
+      \lstinline{move()}
+  \end{itemize}
+\end{frame}
+
+
+\begin{frame}[fragile]
+  \showsection
+  \showsubsection
+
+  \textbf{Wie?}
+  \begin{itemize}
+    \item
+      R-Wert-Referenztypen: \lstinline{&&}
+    \item
+      \lstinline{move()}-Funktion
+  \end{itemize}
+
+  \bigskip
+
+  Literatur:
+  \begin{itemize}
+    \item
+      \url{http://thbecker.net/articles/rvalue_references/section_01.html}
+    \item
+      \url{http://www.artima.com/cppsource/rvalue.html}
+  \end{itemize}
+\end{frame}
+
+\if false
+
+\subsection{Lambda-Ausdrücke}
+
+\begin{frame}[fragile]
+
+  \showsection
+  \showsubsection
+
+  \textbf{Übergabe von Funktionszeigern}
+
+  \medskip
+
+  \begin{lstlisting}
+    int is_smaller (int a, int b)
+    {
+      return a < b;
+    }
+
+    sort (numbers.begin (), numbers.end (), is_smaller);
+  \end{lstlisting}
+
+  \bigskip
+
+  Stattdessen: \newterm{Lambda-Ausdrücke}
+
+\end{frame}
+
+\fi
+
+\nosectionnonumber{\inserttitle}
+
+\begin{frame}
+
+  \shownosectionnonumber
+
+  \begin{itemize}
+    \item[\textbf{1}] \textbf{Einführung}
+      \underconstruction
+      \hfill\makebox(0,0)[br]{\raisebox{2.25ex}{\url{https://gitlab.cvh-server.de/pgerwinski/ad.git}}}
+    \item[\textbf{2}] \textbf{Einführung in C++}
+    \item[\textbf{3}] \textbf{Datenorganisation}
+      \begin{itemize}
+        \item[3.1] Standard-Container-Templates
+        \item[3.2] Iteratoren
+        \item[3.3] Hash-Tabellen
+        \color{medgreen}
+        \item[3.4] Balancierte Bäume
+        \item[3.5] Intelligente Zeiger
+      \end{itemize}
+    \item[\textbf{4}] \textbf{Datenkodierung}
+%      \begin{itemize}
+%        \item Fehlererkennung und -korrektur
+%        \item Kompression
+%        \item Kryptographie
+%      \end{itemize}
+    \item[\textbf{5}] \textbf{Hardwarenahe Algorithmen}
+%      \begin{itemize}
+%        \item FFT, CORDIC, \dots
+%      \end{itemize}
+    \item[\textbf{6}] \textbf{Optimierung}
+%      \begin{itemize}
+%        \item Wegfindung, \dots
+%      \end{itemize}
+    \color{gray}
+    \item[\textbf{7}] \textbf{Numerik}
+  \end{itemize}
+
+\end{frame}
+
+\end{document}

20180503/logo-hochschule-bochum-cvh-text.pdf

+../common/logo-hochschule-bochum-cvh-text.pdf
\ No newline at end of file

20180503/logo-hochschule-bochum.pdf

+../common/logo-hochschule-bochum.pdf
\ No newline at end of file

20180503/pgslides.sty

+../common/pgslides.sty
\ No newline at end of file