GitHub Coding Interview Questions
26 GitHub coding interview problems with full optimal solutions — 12 easy, 10 medium, 4 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an GitHub interviewer values, and a FAQ section.
Showing 4 problems of 26
- #20hardfoundational
20. Minimum Window Substring
Variable sliding window to find the smallest substring containing all target characters — the canonical string-processing hard problem GitHub tests in senior-level loops.
- #21hardfoundational
21. Serialize and Deserialize Binary Tree
Design a codec to convert a binary tree to/from a string, mirroring how GitHub serializes ASTs and repository tree structures for storage and wire transfer.
- #24hardfoundational
24. Merge K Sorted Lists
Merge k sorted linked lists into one sorted list using a min-heap, analogous to how GitHub merges multiple sorted commit streams from different remotes during a fetch.
- #26hardfoundational
26. Trapping Rain Water
Compute water trapped between bars using two-pointer or stack techniques — a classic hard problem GitHub includes in senior engineer interviews to test array reasoning under constraints.
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