Beispiele 21.4.2022

20220414/ad-20220414.tex

@@ -200,16 +200,16 @@
   \begin{lstlisting}
       int prime[5] = { 2, 3, 5, 7, 11 };
       for (int *p = prime; p != prime + 5; p++)
-        cout << *p << endl;
+        std::cout << *p << std::endl;
   \end{lstlisting}
 
   \bigskip
   Iterator als Verallgemeinerung:
   \medskip
   \begin{lstlisting}
-      array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
-      for (array <int, 5>::iterator p = prime.begin (); p != prime.end (); p++)
-        cout << *p << endl;
+      std::array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
+      for (std::array <int, 5>::iterator p = prime.begin (); p != prime.end (); p++)
+        std::cout << *p << std::endl;
   \end{lstlisting}
 \end{frame}
 

20220421/ad-20220421.tex

@@ -151,22 +151,45 @@
   \showsection
   \showsubsection
 
+  \begin{onlyenv}<1>
     Pointer-Arithmetik:
     \medskip
-  \begin{lstlisting}
+    \begin{lstlisting}[gobble=6]
         int prime[5] = { 2, 3, 5, 7, 11 };
         for (int *p = prime; p != prime + 5; p++)
-        cout << *p << endl;
+          std::cout << *p << std::endl;
     \end{lstlisting}
 
     \bigskip
+  \end{onlyenv}
+
   Iterator als Verallgemeinerung:
   \medskip
   \begin{lstlisting}
-      array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
-      for (array <int, 5>::iterator p = prime.begin (); p != prime.end (); p++)
-        cout << *p << endl;
+      std::array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
+      for (std::array <int, 5>::iterator p = prime.begin (); p != prime.end (); p++)
+        std::cout << *p << std::endl;
+  \end{lstlisting}
+
+  \bigskip
+  Mit \lstinline{auto}-Datentyp:
+  \medskip
+  \begin{lstlisting}
+      std::array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
+      for (auto p = prime.begin (); p != prime.end (); p++)
+        std::cout << *p << std::endl;
+  \end{lstlisting}
+
+  \begin{onlyenv}<2->
+    \bigskip
+    Mit Doppelpunkt-Syntax:
+    \medskip
+    \begin{lstlisting}[gobble=6]
+        std::array <int, 5> prime = { { 2, 3, 5, 7, 11 } };
+        for (auto p : prime)
+          std::cout << p << std::endl;
     \end{lstlisting}
+  \end{onlyenv}
 \end{frame}
 
 \subsection{Exceptions}

20220421/sets-1.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  std::set <int> prime = { { 2, 3, 5, 7, 11 }};
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-10.cpp

+#include <iostream>
+#include <set>
+
+bool less (int a, int b)
+{
+  return a > b;
+}
+
+int main ()
+{
+  std::set <int, bool (*) (int, int)> prime (less);
+
+  // "bool (*less) (int a, int b)"
+  // wäre eine Variable "less" vom Typ "Zeiger auf eine Funktion,
+  // die 2 ints erwartet und ein bool zurückgibt".
+  // Um nur den Typen dieses Zeigers zu bekommen, lassen wir den
+  // Bezeichner "less" für die Variable weg.
+
+  // Nur "bool *less (int a, int b)"
+  // wäre eine Funktion "less", die einen Zeiger auf bool zurückgibt
+  // und 2 ints als Parameter erwartet.
+
+  prime.insert (2);
+  prime.insert (3);
+  prime.insert (7);
+  prime.insert (11);
+  prime.insert (13);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-11.cpp

+#include <iostream>
+#include <set>
+
+bool less (int a, int b)
+{
+  return a > b;
+}
+
+int main ()
+{
+  std::set <int, bool (*) (int, int)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-12.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  auto less = [] (int a, int b) { return a > b; };
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-13.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-14.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-15.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [fwd] (int a, int b)
+  {
+    fwd = !fwd;
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-16.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [&fwd] (int a, int b)
+  {
+    fwd = !fwd;
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-17.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  fwd = 0;
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-18.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-19.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [&fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-2.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  std::set <int> prime = { { 2, 3, 7, 11, 13, 17, 19 }};
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-20.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [const &fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-21.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+
+  auto less = [&const fwd] (int a, int b)
+  {
+    if (fwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-22.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+  const bool &cfwd = fwd;
+
+  auto less = [&cfwd] (int a, int b)
+  {
+    if (cfwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}

20220421/sets-23.cpp

+#include <iostream>
+#include <set>
+
+int main ()
+{
+  bool fwd = 1;
+  const bool &cfwd = fwd;
+
+  auto less = [&cfwd] (int a, int b)
+  {
+    cfwd = !cfwd;
+    if (cfwd)
+      return a < b;
+    else
+      return a > b;
+  };
+
+  std::set <int, decltype (less)> prime ({ 2, 3, 7, 11, 13 }, less);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  fwd = 0;
+  prime.insert (5);
+  for (auto p : prime)
+    std::cout << p << " ";
+  std::cout << std::endl;
+  return 0;
+}