Depth-First Tree Traversal | Dataford Interview Questions

Given a binary tree, write a function to perform a depth-first traversal. Return the node values in preorder: visit the current node, then its left subtree, then its right subtree. Use None for an empty tree and represent each node as a dictionary with val, left, and right keys. Implement def dfs_traversal(root): and return a list of values.

Constraints

0 <= number of nodes <= 1000
Each node has integer value val
Each node has at most one left child and one right child
Return values in preorder, current node, left subtree, right subtree

Function Signature

def dfs_traversal(root):

Your question is Depth-First Tree Traversal. 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

Constraints

0 <= number of nodes <= 1000
Each node has integer value val
Each node has at most one left child and one right child
Return values in preorder, current node, left subtree, right subtree

Function Signature

def dfs_traversal(root):

Your question is Depth-First Tree Traversal. 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.