added stack and test file

.vscode/tasks.json

@@ -0,0 +1,28 @@
+{
+    "tasks": [
+        {
+            "type": "cppbuild",
+            "label": "C/C++: gcc.exe build active file",
+            "command": "C:\\ProgramData\\mingw64\\mingw64\\bin\\gcc.exe",
+            "args": [
+                "-fdiagnostics-color=always",
+                "-g",
+                "${file}",
+                "-o",
+                "${fileDirname}\\${fileBasenameNoExtension}.exe"
+            ],
+            "options": {
+                "cwd": "${fileDirname}"
+            },
+            "problemMatcher": [
+                "$gcc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "detail": "Task generated by Debugger."
+        }
+    ],
+    "version": "2.0.0"
+}

highscores.txt

@@ -1 +1,2 @@
+player_name;4980
 player1;3999

makefile

@@ -35,15 +35,28 @@ $(program_obj_filesobj_files): %.o: %.c
 # --------------------------
 # Unit Tests
 # --------------------------
-unitTests:
-	echo "needs to be implemented"
+tets_sources = test_stack.c stack.c
+test_objects = $(test_sources:.c=.o)
+
+test_runner: $(test_objects)
+	$(CC) $(FLAGS) $^ -o $@
+
+unitTests: test_runner
+	@echo "============================="
+	@echo "Running Stack Unit Tests..."
+	@echo "============================="
+	./test_runner
+	@echo "============================="
+	@echo "Stack Unit Tests Finished."
+	@echo "============================="
+
 
 # --------------------------
 # Clean
 # --------------------------
 clean:
 ifeq ($(OS),Windows_NT)
-	del /f *.o doble
+	del /f *.o doble test_runner
 else
-	rm -f *.o doble
+	rm -f *.o doble test_runner
 endif

stack.c

@@ -10,24 +10,71 @@
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data)
 {
+    StackNode *newNode = (StackNode *)malloc(sizeof(StackNode));
+    
+    if(newNode == NULL)
+    {
+        perror("Fehler! Der Speicher für den neuen StackNode konnte nicht allokiert werden!\n");
+        return stack;
+    }
+    
+    newNode->data = data;   //saves data in newNode
+    newNode->next = stack;  //pushes the newNode on top of stack (newNode->next points to previous Top-Node)
 
+    return newNode;
 }
 
 // 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)
+    {
+        perror("Fehler! Stack darf zum poppen nicht leer sein!\n");
+        return stack;
+    }
+    
+    StackNode *old = stack;  //temporary pointer to old top of stack
 
+    stack= stack->next;  //update stack pointer to point to next element
+
+    free(old);  //free the memory of the old StackNode (old->data is not beeing freed)
+    
+    return stack;
 }
 
 // Returns the data of the top element.
 void *top(StackNode *stack)
 {
+    if (stack == NULL)
+    {
+        perror("Fehler! Kann von einem leeren Stack nicht das oberste Element lesen!\n");
+        return NULL;
+    }
+    void *data = stack->data;
 
+    return data;
 }
 
 // Clears stack and releases all memory.
 void clearStack(StackNode *stack)
 {
+    StackNode *current = stack;
+    StackNode *next;
 
+    while (current != NULL)
+    {
+        next = current->next;
+
+        if (current->data != NULL) 
+        {
+            free(current->data);
+            current->data = NULL;
+        }
+
+        free(current);
+        current = NULL;
+        
+        current = next;
+    }
 }

stack.h

@@ -8,6 +8,12 @@ The latest element is taken from the stack. */
 #include <stdlib.h>
 
 //TODO: passenden Datentyp als struct anlegen
+typedef struct StackNode
+{
+    void *data;
+    struct StackNode *next;
+} StackNode;
+
 
 // Pushes data as pointer onto the stack.
 StackNode *push(StackNode *stack, void *data);

test_stack.c

@@ -0,0 +1,141 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "stack.h"
+
+void test_on_empty_stack(void)
+{
+    char *status_a = "leer";
+    char *status_b = "leer";
+    StackNode *stack = NULL;
+
+    StackNode *a = pop(stack);
+    void* b = top(stack);
+
+
+    if (a == NULL)
+    {
+        status_a = "PASSED";
+    }
+    else status_a = "FAILED";
+    
+    if (b == NULL)
+    {
+        status_b = "PASSED";
+    }
+    else status_b = "FAILED";
+
+    printf("Test on empty stack in pop: %s - Expected: NULL, Was: %p\n",status_a, (void*)a);
+    printf("Test on empty stack in top: %s - Expected: NULL, Was: %p\n",status_b, b);
+
+}
+
+void test_push(void)
+{
+    int a[3] = 0;
+    StackNode *stack = NULL;
+
+    for (int i = 1; i < 4; i++)
+    {
+        int *var_push = malloc(sizeof(int));
+
+        if (var_push == NULL) 
+        {
+            printf("Error in allocating memory in test_push!\n");
+            exit(EXIT_FAILURE);
+        }
+
+        *var_push = i;
+        stack = push(stack, var_push);
+
+        void *top_data = top(stack);
+        if (top_data != NULL && *(int*)top_data == i) {
+            a[i-1] = 1; 
+        } else {
+            a[i-1] = 0; 
+        }
+    }
+    
+    if (a[0] == 1 && a[1] == 1 && a[2] == 1)
+    {
+        printf("Test push: SUCCEESS!\n");
+    }
+    
+    else printf("Test pus: FAILED - Expected: all 1, Was: %d, %d, %d\n", a[0], a[1], a[2]);
+
+    stack = clearStack(stack);
+}
+
+void test_pop(void)
+{
+    StackNode *stack = NULL;
+    int *var_push = malloc(sizeof(int));
+
+    if (var_push == NULL) 
+    {
+        fprintf(stderr, "Error in allocating memory in test_pop! Exiting.\n");
+        exit(EXIT_FAILURE);
+    }
+
+    *var_push = 1;
+    stack = push(stack, var_push);
+    stack = pop(stack);
+
+    if (stack == NULL) printf("Test pop: SUCCESS!\n");
+
+    else printf("Test pop: FAIL! - Stack is not empty! Head: %p\n", (void*)stack);
+
+    stack = clearStack(stack);
+}
+
+void test_top(void)
+{
+    StackNode *stack = NULL;
+    int *var_push = malloc(sizeof(int));
+    *var_push = 1;
+    stack = push(stack, var_push);
+    void *b = top(stack);
+
+    if (b != 0 && *(int*)b == 1) printf("Test top: SUCCESS!\n");
+
+    else printf("Test top: FAIL! - Expected 1, was %p\n", b);
+
+    stack = clearStack(stack);
+}
+
+void test_clearStack(void)
+{
+    StackNode *stack = NULL;
+
+    for (int i = 1; i < 4; i++)
+    {
+        int *var_push = malloc(sizeof(int));
+
+        if (var_push == NULL) 
+        {
+            fprintf(stderr, "Error in allocating memory in test_clearStack! Exiting.\n");
+            exit(EXIT_FAILURE); 
+        }
+
+        *var_push = i;
+        stack = push(stack, var_push);
+    }
+
+    stack = clearStack(stack);
+    void *a = top(stack);
+    if (a == NULL) printf("Test clear: SUCESS!\n");
+
+    else printf("Test clear: FAILED! - Expected: NULL, Was:%p\n", a);
+}
+
+int main()
+{
+    printf("============================\nStack Tests\n============================\n");
+
+    test_on_empty_stack();
+    test_push();
+    test_pop();
+    test_top();
+    test_clearStack();
+
+    return EXIT_SUCCESS;
+}