When it is required to create a doubly linked list from a ternary tree, a ‘Node’ class needs to be created. In this class, there are two attributes, the data that is present in the node, and the access to the next node of the linked list.
Another ‘linked_list’ class needs to be created that would have an initialization function, and the head of the node would be initialized to ‘None’.
In a doubly linked list, the nodes have pointers. The current node would have a pointer to the next node as well as the previous node. The last value in the list will have ‘NULL’ value in the next pointer. It can be traversed in both the directions.
Multiple methods are defined by the user to convert the given doubly linked list to a ternary tree, and to print the node values.
Below is a demonstration for the same −
class Node: def __init__(self, my_data): self.right = None self.data = my_data self.left = None self.mid = None class ternary_tree_to_list: def __init__(self): self.root = None self.head = None self.tail = None def convert_ternary_tree_to_list(self, node_val): if node_val is None: return left = node_val.left; mid = node_val.mid; right = node_val.right; if (self.head == None) : self.head = self.tail = node_val node_val.middle = None self.head.left = None self.head.right = None else: self.tail.right = node_val node_val.left = self.tail node_val.mid = None self.tail = node_val self.tail.right = None self.convert_ternary_tree_to_list(left) self.convert_ternary_tree_to_list(mid) self.convert_ternary_tree_to_list(right) def print_it(self): curr = self.head if (self.head == None): print("The list is empty") return print("The nodes are :") while curr != None: print(curr.data) curr = curr.right my_instance = ternary_tree_to_list() print("Elements are being added to the list") my_instance.root = Node(10) my_instance.root.left = Node(14) my_instance.root.mid = Node(24) my_instance.root.right = Node(17) my_instance.root.left.left = Node(22) my_instance.root.left.mid = Node(23) my_instance.root.mid.left = Node(24) my_instance.root.mid.mid = Node(28) my_instance.root.mid.right = Node(30) my_instance.root.right.left = Node(45) my_instance.root.right.mid = Node(50) my_instance.root.right.right = Node(80) my_instance.convert_ternary_tree_to_list(my_instance.root) my_instance.print_it()
Elements are being added to the list The nodes are : 10 14 22 23 24 24 28 30 17 45 50 80