Let us create the tree shown in above diagram
root = Node ( 10 ) NEW_LINE root . left = Node ( 12 ) NEW_LINE root . right = Node ( 15 ) NEW_LINE root . left . left = Node ( 25 ) NEW_LINE root . left . right = Node ( 30 ) NEW_LINE root . right . left = Node ( 36 ) NEW_LINE print   " NEW_LINE INDENT Inorder Tree Traversal NEW_LINE DEDENT " NEW_LINE inorder ( root ) NEW_LINE fixPrevPtr . pre = None NEW_LINE head = BTToDLL ( root ) NEW_LINE print   " NEW_LINE INDENT DLL Traversal NEW_LINE DEDENT " NEW_LINE printList ( head ) NEW_LINE