Binary Tree Left View | Dataford Interview Questions

Given a binary tree, return the left view of the tree. Can you implement this both recursively and iteratively?

Use the function signature def left_view(root):. The input is a binary tree whose nodes expose val, left, and right; return a list containing the first visible node from each level, ordered from the root downward. An empty tree returns an empty list. The examples and test cases represent trees in level-order arrays, with null for missing children.

Constraints

0 <= number of nodes <= 10^4
Node values are integers
The input is a valid binary tree
Return values from the root level through the deepest nonempty level

Function Signature

def left_view(root):

Your question is Binary Tree Left View. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given a binary tree, return the left view of the tree. Can you implement this both recursively and iteratively?

Constraints

0 <= number of nodes <= 10^4
Node values are integers
The input is a valid binary tree
Return values from the root level through the deepest nonempty level

Function Signature

def left_view(root):

Your question is Binary Tree Left View. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.