(2.3) Delete node given only access

CrackingTheCodingInterview/ch02-LinkedLists/LinkedList.py

@@ -32,6 +32,8 @@ def add(self, value):
 
         self.tail = node
 
+        return node
+
     # Remove first node that matches value
     def remove(self, value):
         curr = self.head

CrackingTheCodingInterview/ch02-LinkedLists/delete_node_only_access.py

@@ -0,0 +1,39 @@
+"""
+Implement an algorithm to delete a node in the middle of a singly linked list,
+given only access to that node
+"""
+
+
+from LinkedList import *
+
+
+def delete_node(node):
+    """
+    Delete a node given only access to that node
+
+    Make that node a copy of next node, and delete next node
+    O(1) time
+    O(1) space
+
+    :param node: A linked list node
+    :type node: Node
+    :return: None
+    """
+
+    if node.next is None:
+        node.value = None  # Cannot delete if last node
+    else:
+        node.value = node.next.value
+        node.next = node.next.next
+
+
+a = LinkedList()
+a.add(1)
+a.add(2)
+node = a.add(3)
+a.add(4)
+node_2 = a.add(5)
+delete_node(node)
+print(a)
+delete_node(node_2)
+print(a)