From 2c10463852c9dcef060a8ab1f5d47ce5e3373c4e Mon Sep 17 00:00:00 2001
From: Timo Hertel <hertelti100229@th-nuernberg.de>
Date: Sun, 23 Nov 2025 16:07:25 +0100
Subject: [PATCH] Implement stack, basic test program & makefile entry for the
 test

---
 I2_Dobble/makefile     | 10 ++++--
 I2_Dobble/stack.c      | 33 ++++++++++++++---
 I2_Dobble/stack.h      |  7 +++-
 I2_Dobble/test_stack.c | 80 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 122 insertions(+), 8 deletions(-)
 create mode 100644 I2_Dobble/test_stack.c

diff --git a/I2_Dobble/makefile b/I2_Dobble/makefile
index 1f15f75..e855199 100644
--- a/I2_Dobble/makefile
+++ b/I2_Dobble/makefile
@@ -30,8 +30,14 @@ doble : main.o $(program_obj_files)
 	$(CC) $(FLAGS) $^ -o doble
 
 $(program_obj_filesobj_files): %.o: %.c
-	$(CC) -c $(FLAGS) $^ -o $@
+	$(CC) -c $(FLAGS) -g3 -fPIC $^ -o $@
 
+# --------------------------
+# Stack Tests
+# --------------------------
+stackTests : stack.o test_stack.c
+	$(CC) $(FLAGS) -g3 $^ -o stackTest
+	
 # --------------------------
 # Unit Tests
 # --------------------------
@@ -46,4 +52,4 @@ ifeq ($(OS),Windows_NT)
 	del /f *.o doble
 else
 	rm -f *.o doble
-endif
\ No newline at end of file
+endif
diff --git a/I2_Dobble/stack.c b/I2_Dobble/stack.c
index e3a90d4..6c3c54b 100644
--- a/I2_Dobble/stack.c
+++ b/I2_Dobble/stack.c
@@ -10,24 +10,47 @@
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data)
 {
-
+    //        ,-→ Wenn keine Daten angegeben wird die Liste unverändert zurückgegeben; Ist das sinnvoll? kein Anzeichen, kein Rückgabewert...
+    if (data != NULL)
+    {
+        StackNode *newNode;
+        newNode = (StackNode *)malloc(sizeof(StackNode));
+        newNode->value = data;
+        
+        //         ,-→ bedeutet Liste war leer - das neue Element hat keinen Nachfolger (next = NULL)
+        if (stack == NULL) {
+            newNode->next = NULL;
+        } else {
+            newNode->next = stack;
+        }
+        stack = newNode;
+    }
+    return stack;
 }
 
 // Deletes the top element of the stack (latest added element) and releases its memory. (Pointer to data has to be
 // freed by caller.)
 StackNode *pop(StackNode *stack)
 {
-
+    if(stack != NULL)
+    {
+        StackNode *nextNode = stack->next;
+        free(stack);
+        stack = nextNode;
+    }
+    return stack;
 }
 
 // Returns the data of the top element.
 void *top(StackNode *stack)
 {
-
+    return stack->value;
 }
 
 // Clears stack and releases all memory.
 void clearStack(StackNode *stack)
 {
-
-}
\ No newline at end of file
+    while (stack != NULL) {
+        stack = pop(stack);
+    }
+}
diff --git a/I2_Dobble/stack.h b/I2_Dobble/stack.h
index f7d542d..d1ca13c 100644
--- a/I2_Dobble/stack.h
+++ b/I2_Dobble/stack.h
@@ -7,7 +7,12 @@ The latest element is taken from the stack. */
 
 #include <stdlib.h>
 
-//TODO: passenden Datentyp als struct anlegen
+//DONE: passenden Datentyp als struct anlegen
+typedef struct Node
+{
+  void *value;
+  struct Node* next;
+} StackNode;
 
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data);
diff --git a/I2_Dobble/test_stack.c b/I2_Dobble/test_stack.c
new file mode 100644
index 0000000..60fabd8
--- /dev/null
+++ b/I2_Dobble/test_stack.c
@@ -0,0 +1,80 @@
+#include <bits/types/stack_t.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "stack.h"
+
+void inspectStack(StackNode *stack)
+{    
+    if (stack != NULL)
+    {
+        printf("Der Stack enthält die folgenden Elemente: %d", *(int*)stack->value);
+        while (stack->next != NULL)
+        {
+            printf(" %d", *(int*)stack->next->value);
+            stack = stack->next;
+        }
+        putchar('\n');
+    }
+    else
+    {
+        printf("Der Stack ist leer\n");
+    }
+}
+
+int main()
+{
+    StackNode *stack;
+    stack = NULL; // initialisierung mit NULL -> leere Liste
+    
+    printf("...ein Element wird eingefügt...\n");
+    int toBeRemoved = 42;
+    stack = push(stack, &toBeRemoved);
+    
+    inspectStack(stack);
+
+    printf("...das Element wird wieder entfernt...\n");
+    stack = pop(stack);
+    
+    inspectStack(stack);
+    
+    printf("...pop auf leeren Stack...\n");
+    stack = pop(stack);
+    
+    inspectStack(stack);
+    putchar('\n');
+
+    int data[5] = {1, 2, 3, 4, 5};
+
+    // alle 5 werte der reihe nach auf den Satck legen - 1 unten ... 5 oben
+    for (int i = 0; i < 5; i++)
+    {
+        stack = push(stack, &data[i]);
+    }
+
+    
+    //alle Elemente mit Test-Funktion ausgeben
+    inspectStack(stack);
+    
+    // Elemente stück für Stück ausgeben und entfernen
+    printf("1. Element war: %d\n", *(int*)top(stack));
+    stack = pop(stack);
+    printf("2. Element war: %d\n", *(int*)top(stack));
+    stack = pop(stack);
+    printf("3. Element war: %d\n", *(int*)top(stack));
+    stack = pop(stack);
+    printf("4. Element war: %d\n", *(int*)top(stack));
+    stack = pop(stack);
+    printf("5. Element war: %d\n", *(int*)top(stack));
+}
+
+/*
+int main()
+{
+    UNITY_BEGIN();
+
+    printf("============================\n Stack tests\n============================\n");
+    RUN_TEST(test_createNodeFailsOnZeroData);
+
+    return UNITY_END();
+}
+*/