In the script above we create a dictionary nodes_dic where each element corresponds to a node of a tree.

The key is the value of the root node, whereas the value of each item in the dictionary is the corresponding list of child nodes. For instance, the first dictionary element contains A as the key, and a list of child nodes B and C as the value.

We will create an object of the root node class, and then initialize it with first item in the dictionary:

1let root_node_value = nodes_dic.keys().next().value;
2let root_node_children = nodes_dic.values().next().value;
3let root_node = new TreeNode(root_node_value, root_node_children);

Note: The code snippets above assume that the nodes_dic structure and the TreeNode class or struct are defined appropriately in the respective languages. The exact implementation might vary based on the details of those definitions.