Grokking Tree Coding Patterns for Interviews
The tree patterns that carry most tree questions: level order traversal, root to leaf paths, depth first accumulation and binary search tree invariants. Trees appear in almost every loop, so the return on two focused weeks is high.
Course
Interview Prep
Design Gurus
2 weeks
Intermediate
Subscription
Why trees specifically
Trees show up in a very large share of interview loops, partly because they are easy to state and hard to get exactly right under pressure. Off by one errors on depth, mishandled null children, and traversal chosen by reflex rather than by fit are the usual failure modes.
What it covers
Breadth first level order and its variants, depth first path accumulation, the difference between what you compute on the way down and what you return on the way up, binary search tree properties and validation, and the recursive shape that most tree problems collapse into once you see it.
How to use it
Write the recursive helper signature before writing any body. Deciding what the helper returns, and what it accumulates through parameters, is where tree problems are actually solved or lost.
Best for: anyone whose tree solutions work on the happy path and break on the edge cases.
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