The dictionary has key and value pairs of manager employee relationship, manager key can have multiple employees and those employees can have their own employees like below

data = {
    "Amy": ["Alice", "Charlie"],
    "Alice": ["Akon", "Eve"],
    "Eve": ["Frank", None],
    "Charlie": ["Bob", "Grace"]
}

while I can see all the nodes are getting added in the print statements below, but I am not able to print out the tree properly.

Here’s the code

class TreeNode:
    def __init__(self, key):
        self.key = key
        self.left = None
        self.right = None

def construct_binary_tree(data, root_key):
    if root_key not in data:
        return None
    
    print("Constructing node:", root_key)
    root = TreeNode(root_key)
    if root_key in data:
        children = data[root_key]
        left_child_key = children[0] if children and len(children) > 0 else None
        right_child_key = children[1] if children and len(children) > 1 else None
        print("Left child of", root_key, ":", left_child_key)
        print("Right child of", root_key, ":", right_child_key)
        if left_child_key:
            root.left = construct_binary_tree(data, left_child_key)
        if right_child_key:
            root.right = construct_binary_tree(data, right_child_key)
    
    return root

def print_tree(root, depth=0):
    if root:
        print("   " * depth + f"|-- {root.key}")
        print_tree(root.left, depth + 1)
        print_tree(root.right, depth + 1)

# Given data
data = {
    "Amy": ["Alice", "Charlie"],
    "Alice": ["Akon", "Eve"],
    "Eve": ["Frank", None],
    "Charlie": ["Bob", "Grace"]
}

# Construct binary tree
root_key = next(iter(data))
root = construct_binary_tree(data, root_key)

# Print binary tree in tree format
print_tree(root)

Here’s the output I am seeing

Constructing node: Amy
Left child of Amy : Alice
Right child of Amy : Charlie
Constructing node: Alice
Left child of Alice : Akon
Right child of Alice : Eve
Constructing node: Eve
Left child of Eve : Frank
Right child of Eve : None
Constructing node: Charlie
Left child of Charlie : Bob
Right child of Charlie : Grace
|-- Amy
   |-- Alice
      |-- Eve
   |-- Charlie