Sum of Left Leaves | Dataford Interview Questions

Given a binary tree, calculate the sum of all left leaves.

Represent each node as a dictionary with val, left, and right keys, where an absent child is None. Implement sum_of_left_leaves(root) and return an integer. A left leaf has no children and is the left child of its parent.

Function

def sum_of_left_leaves(root):

Constraints

The tree contains between 0 and 10^5 nodes.
Each node is represented by a dictionary with keys val, left, and right.
-10^4 <= node['val'] <= 10^4
Child references are either another node dictionary or None.

Function Signature

def sum_of_left_leaves(root):

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Problem