Representative Depth-First Search problems
Solve Word Search with backtracking by exploring adjacent cells to match a target word in a grid.
Open problem page#94 Binary Tree Inorder TraversalBinary Tree Inorder Traversal asks you to visit left subtree, node, then right subtree without losing position while moving through the tree.
Open problem page#98 Validate Binary Search TreeValidate Binary Search Tree problem checks if a binary tree satisfies BST properties using tree traversal and state tracking.
Open problem page#99 Recover Binary Search TreeRecover a BST where two nodes are swapped by mistake using in-order traversal and careful state tracking to restore correct structure efficiently.
Open problem page#100 Same TreeCheck whether two binary trees are identical by comparing structure and node values using DFS or BFS traversal strategies efficiently.
Open problem page#101 Symmetric TreeDetermine if a binary tree is symmetric by comparing left and right subtrees using DFS or BFS traversal techniques efficiently.
Open problem page#104 Maximum Depth of Binary TreeFind the maximum depth of a binary tree using traversal techniques to track the longest path from root to leaf.
Open problem page#110 Balanced Binary TreeDetermine if a binary tree is height-balanced using tree traversal and state tracking techniques.
Open problem page#111 Minimum Depth of Binary TreeFind the minimum depth of a binary tree, which is the shortest path from the root node to the nearest leaf node.
Open problem pageDepth-First Search interview questions usually collapse into a small set of repeatable moves. This page groups those GhostInterview problem pages together so you can stay inside one pattern family, compare representative questions, and practice explanations that transfer across multiple prompts. If you are trying to sharpen one interview weakness instead of browsing the entire library, start here.
Why Depth-First Search Matters In Coding Interviews
Interviewers rarely care about the label alone. They care about whether you can recognize when the Depth-First Search pattern applies, explain why it applies, and avoid the failure modes that usually show up under time pressure. That is why this page focuses on the family of problems rather than a single isolated example.
Pattern families that show up here
- Binary-tree traversal and state tracking
- Graph traversal with depth-first search
- Array plus Depth-First Search
Use this page to narrow the session
Start from this topic hub, choose one or two representative problems, and then open the detailed problem pages only after you know which version of the pattern you want to reinforce.
How To Practice This Topic
The best workflow is to keep the prep block narrow. Pick one easy or medium problem to confirm the base pattern, then one medium or hard problem to test whether the explanation still holds when the constraints tighten. Once the logic is stable, move into GhostInterview to rehearse the live explanation flow.
Focus on transfer, not title count
Solving more Depth-First Search titles is less useful than understanding how the same move changes across examples. Try to describe what stays the same and what changes from one problem to the next.
Use the problem page when you want the exact breakdown
This topic hub is the discovery layer. The single-problem pages are where you get the answer-first summary, examples, constraints, approach, complexity, pitfalls, and solver CTA.
How GhostInterview Fits
GhostInterview works best after you know which pattern family you are inside. Use this page to choose the right Depth-First Search problem, then use the solver to get the answer path, complexity framing, and follow-up support without switching into a generic study flow.
FAQ
What does the Depth-First Search topic usually test in interviews?
Depth-First Search questions usually test whether you can spot the underlying pattern quickly, explain the trade-offs, and move from intuition to implementation without losing clarity.
How should I use this Depth-First Search topic page?
Use it as a pattern hub. Start with the representative problems on this page, compare the common approach, and then open the exact problem page when you want the full breakdown.
How many GhostInterview problem pages are in the Depth-First Search group?
This topic page currently groups 252 indexed GhostInterview problem pages under the Depth-First Search family.
Should I practice this topic before harder patterns?
That depends on your current gaps. If Depth-First Search is already a weak spot in interviews, it is usually better to stabilize it first before moving into more advanced or less frequent patterns.
Where does GhostInterview fit once I pick a Depth-First Search problem?
The topic page narrows the pattern family. The problem page gives the exact breakdown. GhostInterview is the solver layer when you need direct help with execution, complexity, and follow-up handling.
Stay close to the same reasoning family
Need direct help once you choose a Depth-First Search problem?
Use GhostInterview as the solver layer after you select the exact prompt. Capture the question, get the answer path and complexity framing, and keep the workflow inside the same topic family.