Implemented Stack and StackList

Aufgabe03a.py

+class Stack(list):
+    def __init__(self, l=[]):
+        self.stack = l
+    
+    def __str__(self):
+        return str(self.stack)
+
+    def push(self, element):
+        self.stack.append(element)
+    
+    def pop(self):
+        element = self.stack[-1]
+        del self.stack[-1]
+        return element
+
+    def top(self):
+        return self.stack[-1]
+
+    def size(self):
+        return len(self.stack)
+
+    def isEmpty(self):
+        return not bool(self.stack)
+
+class ListElement:
+
+    def __init__(self, value, next=None):
+        self.value = value
+        self.next = next
+
+class StackList:
+        
+    def __init__(self, l):
+        self.first_element = ListElement(l[-1])
+        element = self.first_element
+        for value in l[1::-1]:
+            while element.next is not None:
+                element = element.next
+            element.next = ListElement(value)
+    
+    def __str__(self):
+        return_string = ""
+        element = self.first_element
+        while element.next is not None:
+            return_string += str(element.value) + " -> "
+            element = element.next
+        
+        return return_string + str(element.value)
+
+    def push(self, value):
+        self.first_element = ListElement(value, self.first_element)
+    
+    def pop(self):
+        value = self.first_element.value
+        self.first_element = self.first_element.next
+        return value
+    
+    def top(self):
+        return self.first_element.value
+    
+    def size(self):
+        if self.first_element is None:
+            return 0
+        
+        n = 1
+        element = self.first_element
+        while element.next is not None:
+            n += 1
+            element = element.next
+        
+        return n
+
+    def isEmpty(self):
+        return self.first_element is None