Coinbase Coding Interview Questions
28 Coinbase coding interview problems with full optimal solutions — 16 easy, 9 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Coinbase interviewer values, and a FAQ section.
Showing 10 problems of 28
- #4easysometimes asked
4. Remove Duplicates from Sorted Array
Compact a sorted array in place so each element appears once and return the new length. Coinbase uses this to probe pointer-discipline — the same two-pointer trick deduplicates trade prints with the same sequence number.
- #5easysometimes asked
5. Remove Element
Remove all occurrences of a target value from an array in place. Coinbase uses this as a quick filter to confirm you reach for two-pointer compaction before allocating.
- #8easysometimes asked
8. Plus One
Increment a big integer represented as a digit array by one. Coinbase uses this as a warm-up before the inevitable BigInt and precision-handling follow-ups.
- #10easysometimes asked
10. Binary Tree Inorder Traversal
Return the inorder traversal of a binary tree's values. Coinbase asks this to confirm you can do both recursive and iterative tree walks — iterative is the one you'd use to walk a price-level tree without blowing the stack.
- #11easysometimes asked
11. Same Tree
Determine whether two binary trees are structurally identical with equal values. Coinbase asks this as a warm-up for tree-equivalence and snapshot-comparison follow-ups.
- #12easyrarely asked
12. Symmetric Tree
Check whether a binary tree is a mirror of itself. Coinbase uses this to confirm you can recurse on pairs — the same pattern used to compare a bid ladder with its ask mirror.
- #13easysometimes asked
13. Maximum Depth of Binary Tree
Return the depth of a binary tree. Coinbase uses this to verify recursion fundamentals before moving to harder tree problems.
- #14easysometimes asked
14. Balanced Binary Tree
Determine if a binary tree is height-balanced. Coinbase uses this to test the post-order short-circuit pattern — the same trick used to validate constraints across an order-book tree.
- #15easyrarely asked
15. Minimum Depth of Binary Tree
Return the minimum depth — the number of nodes along the shortest path from root to nearest leaf. Coinbase asks this to test whether you spot the asymmetric edge case where one child is null.
- #16easyrarely asked
16. Pascal's Triangle
Generate the first numRows of Pascal's triangle. Coinbase asks this to test array-building discipline and to set up follow-ups on combinatorics (used in risk-pricing).
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