Vorbereitung 16.1.2020

20200109/hp-2019ws-p4.tex

@@ -20,7 +20,7 @@
 % Attribution-ShareAlike 3.0 Unported License along with this
 % document.  If not, see <http://creativecommons.org/licenses/>.
 
-% README: Versuch 16. und 23.1.2020: Objektorientiertes Grafik-Programm
+% README: Versuch 4, 16. und 23.1.2020: Objektorientiertes Grafik-Programm
 
 \documentclass[a4paper]{article}
 

20200116/Tower_of_Hanoi.jpeg

+../common/Tower_of_Hanoi.jpeg
\ No newline at end of file

20200116/dynmem-1.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+  for (int i = 0; i < 3; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/dynmem-2.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+
+  char **new_name = malloc (4 * sizeof (char*));
+  for (int i = 0; i < 3; i++)
+    new_name[i] = name[i];
+  name = new_name;   /* Speicherleck: Array wurde nicht freigegeben! */
+
+  name[3] = "Dieter";
+
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/dynmem-3.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+
+  char **new_name = malloc (4 * sizeof (char*));
+  for (int i = 0; i < 3; i++)
+    new_name[i] = name[i];
+  free (name);
+  name = new_name;   /* kein Speicherleck: Array wurde freigegeben. */
+
+  name[3] = "Dieter";
+
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/dynmem-4.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+
+  char **new_name = malloc (4 * sizeof (char*));
+  for (int i = 0; i < 3; i++)
+    new_name[i] = name[i];
+  free (name);
+  name = new_name;
+
+  name[3] = "Dieter";
+
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  free (new_name);   /* Fehler: Array wurde bereits freigegeben! */
+  return 0;
+}

20200116/dynmem-5.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+
+  char **new_name = malloc (4 * sizeof (char*));
+  for (int i = 0; i < 3; i++)
+    new_name[i] = name[i];
+  free (name);
+  name = new_name;
+  new_name = NULL;   /* Zeiger wird nicht mehr gebraucht. */
+
+  name[3] = "Dieter";
+
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/dynmem-6.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+  name = realloc (name, 4 * sizeof (char));
+  name[3] = "Dieter";        /* Fehler: ^ "*" vergessen; zu wenig Speicher */
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/dynmem-7.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main (void)
+{
+  char **name = malloc (3 * sizeof (char *));
+  name[0] = "Anton";
+  name[1] = "Berthold";
+  name[2] = "Caesar";
+  name = realloc (name, 4 * sizeof (char *));
+  name[3] = "Dieter";
+  for (int i = 0; i < 4; i++)
+    printf ("%s\n", name[i]);
+  free (name);
+  return 0;
+}

20200116/hello-gtk.png

+../common/hello-gtk.png
\ No newline at end of file

20200116/landau-symbols-2.pdf

+../common/landau-symbols-2.pdf
\ No newline at end of file

20200116/landau-symbols-3.pdf

+../common/landau-symbols-3.pdf
\ No newline at end of file

20200116/landau-symbols.pdf

+../common/landau-symbols.pdf
\ No newline at end of file

20200116/objects-1.c

+#include <stdio.h>
+
+typedef struct
+{
+  int type;
+} t_base;
+
+typedef struct
+{
+  int type;
+  int content;
+} t_integer;
+
+typedef struct
+{
+  int type;
+  char *content;
+} t_string;
+
+int main (void)
+{
+  t_integer i = { 1, 42 };
+  t_string s = { 2, "Hello, world!" };
+
+  t_base *object[] = { &i, &s };
+
+  return 0;
+}

20200116/objects-10.c

+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE    0
+#define T_INTEGER 1
+#define T_STRING  2
+
+typedef struct
+{
+  int type;
+  void (* print) (t_object *this);
+} t_base;
+
+typedef struct
+{
+  int type;
+  void (* print) (t_object *this);
+  int content;
+} t_integer;
+
+typedef struct
+{
+  int type;
+  void (* print) (t_object *this);
+  char *content;
+} t_string;
+
+typedef union
+{
+  t_base base;
+  t_integer integer;
+  t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+  printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+  printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+  t_object *p = malloc (sizeof (t_integer));
+  p->integer.type = T_INTEGER;
+  p->integer.print = print_integer;
+  p->integer.content = i;
+  return p;
+}
+
+t_object *new_string (char *s)
+{
+  t_object *p = malloc (sizeof (t_string));
+  p->string.type = T_STRING;
+  p->string.print = print_string;
+  p->string.content = s;
+  return p;
+}
+
+int main (void)
+{
+  t_object *object[] = { new_integer (42),
+                         new_string ("Hello, world!"),
+                         NULL };
+
+  for (int i = 0; object[i]; i++)
+    object[i]->base.print (object[i]);
+
+  return 0;
+}

20200116/objects-11.c

+#include <stdio.h>
+#include <stdlib.h>
+
+#define T_BASE    0
+#define T_INTEGER 1
+#define T_STRING  2
+
+union t_object;
+
+typedef struct
+{
+  int type;
+  void (* print) (union t_object *this);
+} t_base;
+
+typedef struct
+{
+  int type;
+  void (* print) (union t_object *this);
+  int content;
+} t_integer;
+
+typedef struct
+{
+  int type;
+  void (* print) (union t_object *this);
+  char *content;
+} t_string;
+
+typedef union t_object
+{
+  t_base base;
+  t_integer integer;
+  t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+  printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+  printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+  t_object *p = malloc (sizeof (t_integer));
+  p->integer.type = T_INTEGER;
+  p->integer.print = print_integer;
+  p->integer.content = i;
+  return p;
+}
+
+t_object *new_string (char *s)
+{
+  t_object *p = malloc (sizeof (t_string));
+  p->string.type = T_STRING;
+  p->string.print = print_string;
+  p->string.content = s;
+  return p;
+}
+
+int main (void)
+{
+  t_object *object[] = { new_integer (42),
+                         new_string ("Hello, world!"),
+                         NULL };
+
+  for (int i = 0; object[i]; i++)
+    object[i]->base.print (object[i]);
+
+  return 0;
+}

20200116/objects-12.c

+#include <stdio.h>
+#include <stdlib.h>
+
+union t_object;
+
+typedef struct
+{
+  void (* print) (union t_object *this);
+} t_base;
+
+typedef struct
+{
+  void (* print) (union t_object *this);
+  int content;
+} t_integer;
+
+typedef struct
+{
+  void (* print) (union t_object *this);
+  char *content;
+} t_string;
+
+typedef union t_object
+{
+  t_base base;
+  t_integer integer;
+  t_string string;
+} t_object;
+
+void print_integer (t_object *this)
+{
+  printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+  printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_object *new_integer (int i)
+{
+  t_object *p = malloc (sizeof (t_integer));
+  p->integer.print = print_integer;
+  p->integer.content = i;
+  return p;
+}
+
+t_object *new_string (char *s)
+{
+  t_object *p = malloc (sizeof (t_string));
+  p->string.print = print_string;
+  p->string.content = s;
+  return p;
+}
+
+int main (void)
+{
+  t_object *object[] = { new_integer (42),
+                         new_string ("Hello, world!"),
+                         NULL };
+
+  for (int i = 0; object[i]; i++)
+    object[i]->base.print (object[i]);
+
+  return 0;
+}

20200116/objects-13.c

+#include <stdio.h>
+#include <stdlib.h>
+
+union t_object;
+struct t_vmt;
+
+typedef struct
+{
+  struct t_vmt *vmt;
+} t_base;
+
+typedef struct
+{
+  struct t_vmt *vmt;
+  int content;
+} t_integer;
+
+typedef struct
+{
+  struct t_vmt *vmt;
+  char *content;
+} t_string;
+
+typedef union t_object
+{
+  t_base base;
+  t_integer integer;
+  t_string string;
+} t_object;
+
+typedef struct t_vmt
+{
+  void (* print) (union t_object *this);
+} t_vmt;
+
+void print_integer (t_object *this)
+{
+  printf ("Integer: %d\n", this->integer.content);
+}
+
+void print_string (t_object *this)
+{
+  printf ("String: \"%s\"\n", this->string.content);
+}
+
+t_vmt vmt_integer = { print_integer };
+t_vmt vmt_string = { print_string };
+
+t_object *new_integer (int i)
+{
+  t_object *p = malloc (sizeof (t_integer));
+  p->integer.vmt = &vmt_integer;
+  p->integer.content = i;
+  return p;
+}
+
+t_object *new_string (char *s)
+{
+  t_object *p = malloc (sizeof (t_string));
+  p->integer.vmt = &vmt_string;
+  p->string.content = s;
+  return p;
+}
+
+int main (void)
+{
+  t_object *object[] = { new_integer (42),
+                         new_string ("Hello, world!"),
+                         NULL };
+
+  for (int i = 0; object[i]; i++)
+    object[i]->base.vmt->print (object[i]);
+
+  return 0;
+}