implement_stack_linkedList

Author: AnushreeBagchi

implement_stack_linkedList.py

@@ -0,0 +1,62 @@
+class Node: 
+    def __init__(self, value):
+        self.value = value
+        self.next = None
+
+class Stack:
+    def __init__(self):
+        self.head = None
+        self.num_elements = 0
+    def to_list(self):
+        py_list = []
+        node = self.head
+        while node:
+            py_list.append(node.value)
+            node = node.next
+        return py_list
+    def push(self, value):
+        if self.head is None:
+            self.head = Node(value)
+        else:
+            new_node = Node(value)
+            new_node.next = self.head
+            self.head = new_node
+        self.num_elements += 1
+    def size(self):
+        return self.num_elements
+    def is_empty(self):
+        return self.num_elements == 0   
+    def pop(self):
+        if self.head is None:
+            return None
+        value = self.head.value
+        self.head = self.head.next
+        self.num_elements -=1
+        return value
+
+
+stack = Stack()
+stack.push(10)
+stack.push(20)
+stack.push(30)
+stack.push(40)
+stack.push(50)
+
+# Test size
+print ("Pass" if (stack.size() == 5) else "Fail")
+
+# Test pop
+print ("Pass" if (stack.pop() == 50) else "Fail")
+
+# Test push
+stack.push(60)
+print ("Pass" if (stack.pop() == 60) else "Fail")
+print ("Pass" if (stack.pop() == 40) else "Fail")
+print ("Pass" if (stack.pop() == 30) else "Fail")
+stack.push(50)
+print ("Pass" if (stack.size() == 3) else "Fail")
+
+
+
+
+