added ws202425 courses

2024_Grundlagen_Betriebssysteme_Rechnernetze/uebung-0-stack/stack.c

@@ -0,0 +1,46 @@
+#include "stack.h"
+#include <stdlib.h>
+
+stack_t *stack_create(size_t size) {
+    stack_t* stack = (stack_t*) malloc(sizeof(stack_t));
+    if (stack == NULL) {
+        return NULL;
+    }
+    stack->array = (char*) malloc(size * sizeof(char));
+    if (stack->array == NULL) {
+        free(stack);
+        return NULL;
+    }
+    stack->size = size;
+    stack->length = 0;
+    return stack;
+}
+
+void stack_delete(stack_t *stack) {
+    if (stack != NULL) {
+        free(stack->array);
+        free(stack);
+    }
+}
+
+size_t stack_length(stack_t *stack) {
+    return stack->length; 
+}
+
+int stack_push(stack_t *stack, char c) {
+    if (stack->length >= stack->size) {
+        return -1;
+    }
+    stack->array[stack->length] = c;
+    stack->length++;
+    return 0;
+}
+
+int stack_pop(stack_t *stack, char *dest) {
+    if (stack->length == 0) {
+        return -1;
+    }
+    *dest = stack->array[stack->length - 1];
+    stack->length--;
+    return 0;
+}