Musterlösung Aufgabe 3 4.2.2021, Aktualisierung README.md

20210204/loesung-3-1.c

+#include <stdio.h>
+#include <stdint.h>
+
+uint8_t buffer = 0;
+
+void bit_array_set (int i, int value)
+{
+  uint8_t mask = 1 << i;
+  if (value)
+    buffer |= mask;
+  else
+    buffer &= ~mask;
+}
+
+void bit_array_flip (int i)
+{
+  uint8_t mask = 1 << i;
+  buffer ^= mask;
+}
+
+int bit_array_get (int i)
+{
+  uint8_t mask = 1 << i;
+  if (buffer & mask)
+    return 1;
+  else
+    return 0;
+}
+
+void output (void)
+{
+  for (int i = 0; i < 8; i++)
+    {
+      if (i % 4 == 0)
+        printf (" ");
+      printf ("%d", bit_array_get (i));
+    }
+  printf ("\n");
+}
+
+int main (void)
+{
+  output ();
+  bit_array_set (2, 1);
+  output ();
+  bit_array_flip (7);
+  output ();
+  bit_array_set (2, 0);
+  output ();
+}

20210204/loesung-3-2.c

+#include <stdio.h>
+#include <stdint.h>
+
+#define LENGTH 32
+
+uint8_t buffer[LENGTH / 8] = { 0, 0, 0, 0 };
+
+void bit_array_set (int i, int value)
+{
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (value)
+    buffer[byte_index] |= mask;
+  else
+    buffer[byte_index] &= ~mask;
+}
+
+void bit_array_flip (int i)
+{
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  buffer[byte_index] ^= mask;
+}
+
+int bit_array_get (int i)
+{
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (buffer[byte_index] & mask)
+    return 1;
+  else
+    return 0;
+}
+
+void output (void)
+{
+  for (int i = 0; i < LENGTH; i++)
+    {
+      if (i % 4 == 0)
+        printf (" ");
+      printf ("%d", bit_array_get (i));
+    }
+  printf ("\n");
+}
+
+int main (void)
+{
+  output ();
+  bit_array_set (12, 1);
+  output ();
+  bit_array_flip (31);
+  output ();
+  bit_array_set (12, 0);
+  output ();
+}

20210204/loesung-3-3.c

+#include <stdio.h>
+#include <stdint.h>
+#include <error.h>
+
+#define LENGTH 29
+#define BYTES ((LENGTH + 7) / 8)
+
+uint8_t buffer[BYTES] = { 0, 0, 0, 0 };
+
+void check_index (int i)
+{
+  if (i < 0 || i >= LENGTH)
+    error (1, 0, "index %d out of range (0, ..., %d)", i, LENGTH - 1);
+}
+
+void bit_array_set (int i, int value)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (value)
+    buffer[byte_index] |= mask;
+  else
+    buffer[byte_index] &= ~mask;
+}
+
+void bit_array_flip (int i)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  buffer[byte_index] ^= mask;
+}
+
+int bit_array_get (int i)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (buffer[byte_index] & mask)
+    return 1;
+  else
+    return 0;
+}
+
+void output (void)
+{
+  for (int i = 0; i < LENGTH; i++)
+    {
+      if (i % 4 == 0)
+        printf (" ");
+      printf ("%d", bit_array_get (i));
+    }
+  printf ("\n");
+}
+
+int main (void)
+{
+  output ();
+  bit_array_set (12, 1);
+  output ();
+  bit_array_flip (28);
+  output ();
+  bit_array_set (12, 0);
+  output ();
+  bit_array_flip (31);
+  output ();
+}

20210204/loesung-3-4.c

+#include <stdio.h>
+#include <stdint.h>
+#include <error.h>
+#include <stdlib.h>
+
+int length = 0;
+int bytes = 0;
+uint8_t *buffer = NULL;
+
+void bit_array_init (int n)
+{
+  length = n;
+  bytes = (length + 7) / 8;
+  if (buffer)
+    free (buffer);
+  buffer = malloc (bytes * sizeof (uint8_t));
+  for (int i = 0; i < bytes; i++)
+    buffer[i] = 0;
+}
+
+void bit_array_resize (int new_n)
+{
+  length = new_n;
+  bytes = (length + 7) / 8;
+  buffer = realloc (buffer, bytes * sizeof (uint8_t));
+}
+
+void bit_array_done (void)
+{
+  free (buffer);
+  buffer = NULL;
+  length = 0;
+  bytes = 0;
+}
+
+void check_index (int i)
+{
+  if (!buffer)
+    error (1, 0, "array not initialised");
+  if (i < 0 || i >= length)
+    error (1, 0, "index %d out of range (0, ..., %d)", i, length - 1);
+}
+
+void bit_array_set (int i, int value)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (value)
+    buffer[byte_index] |= mask;
+  else
+    buffer[byte_index] &= ~mask;
+}
+
+void bit_array_flip (int i)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  buffer[byte_index] ^= mask;
+}
+
+int bit_array_get (int i)
+{
+  check_index (i);
+  int byte_index = i / 8;
+  int bit_index = i % 8;
+  uint8_t mask = 1 << bit_index;
+  if (buffer[byte_index] & mask)
+    return 1;
+  else
+    return 0;
+}
+
+void output (void)
+{
+  for (int i = 0; i < length; i++)
+    {
+      if (i % 4 == 0)
+        printf (" ");
+      printf ("%d", bit_array_get (i));
+    }
+  printf ("\n");
+}
+
+int main (void)
+{
+  bit_array_init (29);
+  output ();
+  bit_array_set (12, 1);
+  output ();
+  bit_array_flip (28);
+  output ();
+  bit_array_set (12, 0);
+  output ();
+  bit_array_flip (31);
+  output ();
+  bit_array_done ();
+}

README.md

@@ -29,6 +29,7 @@ Vortragsfolien und Beispiele:
  * [21.01.2021: Hardwarenahe Programmierung: Interrupts, volatile-Variable, Byte-Reihenfolge – Endianness, Binärdarstellung negativer Zahlen, Speicherausrichtung – Alignment](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210121/hp-20210121.pdf) [**(Beispiele)**](https://gitlab.cvh-server.de/pgerwinski/hp/tree/2020ws/20210121/)
  * [28.01.2021: Objektorientierte Programmierung](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210128/hp-20210128.pdf) [**(Beispiele)**](https://gitlab.cvh-server.de/pgerwinski/hp/tree/2020ws/20210128/)
  * [04.02.2021: Objektorientierte Programmierung: virtuelle Methoden](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210204/hp-20210204.pdf) [**(Beispiele)**](https://gitlab.cvh-server.de/pgerwinski/hp/tree/2020ws/20210204/)
+ * [11.02.2021: Objektorientierte Programmierung: virtuelle Methoden](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210211/hp-20210211.pdf) [**(Beispiele)**](https://gitlab.cvh-server.de/pgerwinski/hp/tree/2020ws/20210211/)
  * [alle in 1 Datei](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/hp-slides-2020ws.pdf)
 
 Übungsaufgaben:
@@ -45,6 +46,7 @@ Vortragsfolien und Beispiele:
  * [21.01.2021: Trickprogrammierung, Thermometer-Baustein an I²C-Bus, LED-Blinkmuster](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210121/hp-uebung-20210121.pdf)
  * [28.01.2021: Speicherformate von Zahlen, Personen-Datenbank, objektorientierte Tier-Datenbank](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210128/hp-uebung-20210128.pdf)
  * [04.02.2021: Objektorientierte Tier-Datenbank (Neuauflage), Iterationsfunktionen, dynamisches Bit-Array](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210204/hp-uebung-20210204.pdf)
+ * [11.02.2021: Stack-Operationen, einfach und doppelt verkettete Listen, ternärer Baum](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210211/hp-uebung-20210211.pdf)
 
 Musterlösungen:
 ---------------
@@ -59,6 +61,7 @@ Musterlösungen:
  * [21.01.2021: Trickprogrammierung, Thermometer-Baustein an I²C-Bus, LED-Blinkmuster](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210121/hp-musterloesung-20210121.pdf)
  * [28.01.2021: Speicherformate von Zahlen, Personen-Datenbank, objektorientierte Tier-Datenbank](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210128/hp-musterloesung-20210128.pdf)
  * [04.02.2021: Objektorientierte Tier-Datenbank (Neuauflage), Iterationsfunktionen, dynamisches Bit-Array](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210204/hp-musterloesung-20210204.pdf)
+ * [11.02.2021: Stack-Operationen, einfach und doppelt verkettete Listen, ternärer Baum](https://gitlab.cvh-server.de/pgerwinski/hp/raw/2020ws/20210211/hp-musterloesung-20210211.pdf)
 
 Tafelbilder:
 ------------

hp-slides-2020ws.tex

@@ -34,4 +34,6 @@
   \includepdf[pages=-]{20210128/hp-20210128.pdf}
   \pdfbookmark[1]{04.02.2021: Objektorientierte Programmierung: virtuelle Methoden}{20210204}
   \includepdf[pages=-]{20210204/hp-20210204.pdf}
+  \pdfbookmark[1]{11.02.2021: Objektorientierte Programmierung: virtuelle Methoden}{20210211}
+  \includepdf[pages=-]{20210211/hp-20210211.pdf}
 \end{document}