Visualization of a Binary Tree Creation

Let’s understand binary tree creation details by a little example.

Class Definition

The Definition ofTreeNode is the following.

class TreeNode:
    
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

Two Variables

• root — the variable is useful to access the binary tree
• curnode — the variable is for iteration inside of the binary tree

root = curnode = TreeNode(val=1)

two tree node object

Create Children

Creating two child tree node, their parent node curnode is used

curnode.left = TreeNode(1)
curnode.right = TreeNode(2)

Iteration within Tree

The variable curnodeis iterated to a new tree node

curnode = curnode.left
curnode.left = TreeNode(3)