Notizen 20.4.2023: Stundenplan-Algorithmus; Beispiele 27.4.2023

20230420/ad-20230420.txt

+Stundenplan-Algorithmus, 20.04.2023, 17:27:42
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Zum Algorithmus von FET: https://lalescu.ro/liviu/fet/doc/en/generation-algorithm-description.html
+
+gegeben: Input
+ - Liste der Lehrveranstaltungen
+ - Liste der Studierendengruppen mit zeitlichen Einschränkungen
+ - Liste der Lehrenden mit zeitlichen Einschränkungen
+
+für jede Lehrveranstaltung:
+  Schritt 1: Nächstbesten freien Platz im Stundenplan wählen
+  Vorbedingungen: einige Lehrveranstaltungen wurden bereits plaziert
+  Dafür benötigt:
+   - Funktion, die auf Konflikte prüft: Bitmasken verwenden?
+   - Funktion, die den nächsten freien Slot findet
+  Schritt 2: Falls es keinen freien Platz gibt:
+   - irgendwas anderes wegschieben
+   - Was??? Wohin???
+
+--> Neue Idee
+
+  Falls es keinen freien Platz gibt:
+    Reihenfolge der "freifliegenden" Lehrveranstaltungen ändern
+    von vorne beginnen
+
+Stundenplan als Bitmaske:
+  4 * 11 + 1 = 45 Viertelstunden pro Tag an 5 Tagen pro Woche
+  = (4 * 11 + 1) * 5 = 225 Bit
+
+Bitmasken für Module berechnen.
+Mit dem Modul beginnen, das die wenigsten Möglichkeiten hat.

20230427/exceptions-0.cpp

+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+  int a = 42;
+  int b = 0;
+  if (b == 0)
+    {
+      cout << "Irgendwas ist schiefgelaufen: Ganzzahldivision durch Null" << endl;
+    }
+  else
+    {
+      int c = a / b;
+      cout << "c = " << c << endl;
+    }
+  return 0;
+}

20230427/exceptions-1.cpp

+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+  try
+    {
+      int a = 42;
+      int b = 0;
+      if (b == 0)
+        throw "Ganzzahldivision durch Null";
+      int c = a / b;
+      cout << "c = " << c << endl;
+    }
+  catch (const char *msg)
+    {
+      cout << "Irgendwas ist schiefgelaufen: " << msg << endl;
+    }
+  return 0;
+}

20230427/exceptions-10.cpp

+#include <iostream>
+#include <sstream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+  static const char *buffer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  virtual const char *what () const noexcept;
+};
+
+const char *philosophy_exception::what () const noexcept
+{
+  return buffer;
+//  ostringstream buffer;
+//  buffer << "philosophy exception #" << answer;
+//  return buffer.str ().c_str ();
+}
+
+const char *philosophy_exception::buffer = "Marvin";
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 42)
+      cout << "And what was the question?" << endl;
+    else
+      throw philosophy_exception (answer);
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception: " << e.what () << endl;
+  }
+  return 0;
+}

20230427/exceptions-11.cpp

+#include <iostream>
+#include <sstream>
+#include <string.h>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+  static char buffer[42];
+public:
+  philosophy_exception (int a) { answer = a; }
+  virtual const char *what () const noexcept;
+};
+
+const char *philosophy_exception::what () const noexcept
+{
+  ostringstream tmp_buffer;
+  tmp_buffer << "philosophy exception #" << answer;
+  strcpy (buffer, tmp_buffer.str ().c_str ());
+  return buffer;
+}
+
+char philosophy_exception::buffer[42] = "Marvin";
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 42)
+      cout << "And what was the question?" << endl;
+    else
+      throw philosophy_exception (answer);
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception: " << e.what () << endl;
+  }
+  return 0;
+}

20230427/exceptions-1a.cpp

+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+  int a = 42;
+  int b = 0;
+  if (b == 0)
+    {
+      cout << "Irgendwas ist schiefgelaufen: " << "Ganzzahldivision durch Null" << endl;
+      return 1;
+    }
+  int c = a / b;
+  cout << "c = " << c << endl;
+  return 0;
+}

20230427/exceptions-1b.cpp

+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+  try
+    {
+      int a = 42;
+      int b = 0;
+      if (b == 0)
+        throw "Ganzzahldivision durch Null";
+      int c = a / b;
+      cout << "c = " << c << endl;
+    }
+  catch (int msg)
+    {
+      cout << "Irgendwas ist schiefgelaufen: " << msg << endl;
+    }
+  return 0;
+}

20230427/exceptions-1c.cpp

+#include <iostream>
+
+using namespace std;
+
+int main ()
+{
+  try
+    {
+      int a = 42;
+      int b = 0;
+      int c = a / b;
+      cout << "c = " << c << endl;
+    }
+  catch (int msg)
+    {
+      cout << "Irgendwas ist schiefgelaufen: " << msg << endl;
+    }
+  return 0;
+}

20230427/exceptions-2.cpp

+#include <iostream>
+
+using namespace std;
+
+void check_answer (int answer)
+{
+  if (answer != 42)
+    {
+      try
+      {
+        if (answer == 10)
+          throw answer;
+        else if (answer == 137)
+          throw "alpha";
+      }
+      catch (int e)
+      {
+        cout << "Yeah!" << endl;
+        throw;
+      }
+      throw "bullshit";
+    }
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 23)
+      throw answer;
+    else
+      check_answer (answer);
+  }
+  catch (const char *e)
+  {
+    cout << "caught string exception: " << e << endl;
+  }
+  cout << "And what was the question?" << endl;
+  return 0;
+}

20230427/exceptions-2a.cpp

+#include <iostream>
+
+using namespace std;
+
+void check_answer (int answer)
+{
+  if (answer != 42)
+    {
+      try
+      {
+        if (answer == 10)
+          throw answer;
+        if (answer == 137)
+          throw "alpha";
+      }
+      catch (int e)
+      {
+        cout << "Yeah!" << endl;
+        throw;
+      }
+      throw "bullshit";
+    }
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 23)
+      throw answer;
+    check_answer (answer);
+  }
+  catch (const char *e)
+  {
+    cout << "caught string exception: " << e << endl;
+  }
+  cout << "And what was the question?" << endl;
+  return 0;
+}

20230427/exceptions-2b.cpp

+#include <iostream>
+
+using namespace std;
+
+void check_answer (int answer)
+{
+  if (answer != 42)
+    {
+      try
+      {
+        if (answer == 10)
+          throw answer;
+        if (answer == 137)
+          throw "alpha";
+      }
+      catch (int e)
+      {
+        cout << "Yeah!" << endl;
+        throw;
+      }
+      throw "bullshit";
+    }
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 23)
+      throw answer;
+    check_answer (answer);
+  }
+  catch (const char *e)
+  {
+    cout << "caught string exception: " << e << endl;
+  }
+  catch (int e)
+  {
+    cout << "caught integer exception: " << e << endl;
+  }
+  cout << "And what was the question?" << endl;
+  return 0;
+}

20230427/exceptions-2c.cpp

+#include <iostream>
+
+using namespace std;
+
+void check_answer (int answer)
+{
+  if (answer == 42)
+    return;
+  try
+  {
+    if (answer == 10)
+      throw answer;
+    if (answer == 137)
+      throw "alpha";
+  }
+  catch (int e)
+  {
+    cout << "Yeah!" << endl;
+    throw;
+  }
+  throw "bullshit";
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 23)
+      throw answer;
+    check_answer (answer);
+  }
+  catch (const char *e)
+  {
+    cout << "caught string exception: " << e << endl;
+  }
+  catch (int e)
+  {
+    cout << "caught integer exception: " << e << endl;
+  }
+  cout << "And what was the question?" << endl;
+  return 0;
+}

20230427/exceptions-3.cpp

+#include <iostream>
+
+using namespace std;
+
+void check_answer (int answer)
+{
+  if (answer != 42)
+    {
+      try
+      {
+        if (answer == 10)
+          throw answer;
+        else if (answer == 137)
+          throw "alpha";
+      }
+      catch (int e)
+      {
+        cout << "Yeah!" << endl;
+      }
+      throw "bullshit";
+    }
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 23)
+      throw answer;
+    else
+      check_answer (answer);
+  }
+  catch (const char *e)
+  {
+    cout << "caught string exception: " << e << endl;
+  }
+  cout << "And what was the question?" << endl;
+  return 0;
+}

20230427/exceptions-4.cpp

+#include <iostream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+};
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer != 42)
+      throw philosophy_exception (answer);
+    cout << "And what was the question?" << endl;
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception" << endl;
+  }
+  return 0;
+}

20230427/exceptions-5.cpp

+#include <iostream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  int get_answer () { return answer; }
+};
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer != 42)
+      throw philosophy_exception (answer);
+    cout << "And what was the question?" << endl;
+  }
+  catch (philosophy_exception &e)
+  {
+    cout << "caught philosophy exception: " << e.get_answer () << endl;
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception" << endl;
+  }
+  return 0;
+}

20230427/exceptions-6.cpp

+#include <iostream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  int get_answer () { return answer; }
+};
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer != 42)
+      throw philosophy_exception (answer);
+    cout << "And what was the question?" << endl;
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception" << endl;
+  }
+  catch (philosophy_exception &e)
+  {
+    cout << "caught philosophy exception: " << e.get_answer () << endl;
+  }
+  return 0;
+}

20230427/exceptions-7.cpp

+#include <iostream>
+#include <sstream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  virtual const char *what ();
+};
+
+const char *philosophy_exception::what ()
+{
+  ostringstream buffer;
+  buffer << "philosophy exception #" << answer;
+  return buffer.str ().c_str ();
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 42)
+      cout << "And what was the question?" << endl;
+    else
+      throw philosophy_exception (answer);
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception: " << e.what () << endl;
+  }
+  return 0;
+}

20230427/exceptions-8.cpp

+#include <iostream>
+#include <sstream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  virtual const char *what () const noexcept;
+};
+
+const char *philosophy_exception::what () const noexcept
+{
+  ostringstream buffer;
+  buffer << "philosophy exception #" << answer;
+  return buffer.str ().c_str ();
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 42)
+      cout << "And what was the question?" << endl;
+    else
+      throw philosophy_exception (answer);
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception: " << e.what () << endl;
+  }
+  return 0;
+}

20230427/exceptions-9.cpp

+#include <iostream>
+#include <sstream>
+
+using namespace std;
+
+class philosophy_exception: public exception
+{
+  int answer;
+public:
+  philosophy_exception (int a) { answer = a; }
+  virtual const char *what () const noexcept;
+};
+
+const char *philosophy_exception::what () const noexcept
+{
+  return "Marvin";
+//  ostringstream buffer;
+//  buffer << "philosophy exception #" << answer;
+//  return buffer.str ().c_str ();
+}
+
+int main ()
+{
+  int answer;
+  cout << "What's your answer? ";
+  cin >> answer;
+  try
+  {
+    if (answer == 42)
+      cout << "And what was the question?" << endl;
+    else
+      throw philosophy_exception (answer);
+  }
+  catch (exception &e)
+  {
+    cout << "caught exception: " << e.what () << endl;
+  }
+  return 0;
+}

20230427/exceptions-what.cpp

+// exception::what
+#include <iostream>       // std::cout
+#include <exception>      // std::exception
+
+struct ooops : std::exception {
+  virtual const char* what() const noexcept {return "Ooops!\n";}
+};
+
+int main () {
+  try {
+      throw ooops();
+  } catch (std::exception& ex) {
+      std::cout << ex.what();
+  }
+  return 0;
+}