Glassdoor Coding Interview Questions
26 Glassdoor coding interview problems with full optimal solutions — 17 easy, 7 medium, 2 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Glassdoor interviewer values, and a FAQ section.
Showing 17 problems of 26
- #24easyfoundational
24. Best Time to Buy and Sell Stock
Glassdoor coaches job-seekers on offer timing — and this single-pass min-tracking problem is their go-to warmup that doubles as a filter for candidates who conflate 'track the minimum seen' with 'compare all pairs'.
- #25easyfoundational
25. Contains Duplicate
Deduplicating reviews before they're stored is one of Glassdoor's first data-quality gates — this Set-based duplicate-detection problem is their simplest warmup and a signal that you know O(n) beats sort-based O(n log n).
- #26easyfoundational
26. Valid Anagram
Glassdoor's search team normalizes job-title keywords so that 'Engineer Software' and 'Software Engineer' hit the same results — this character-frequency comparison is the pattern behind that normalization and a common screen opener.
- #1easyfoundational
1. Two Sum
Find two indices in an array whose values sum to a target — Glassdoor uses this to test whether you can replace an O(n^2) scan with a hash-lookup.
- #2easyfoundational
2. Valid Parentheses
Validate a string of brackets using a stack — Glassdoor uses this as a warm-up to gauge basic data-structure fluency.
- #3easyfoundational
3. Merge Two Sorted Lists
Merge two sorted linked lists into one sorted list — Glassdoor uses this to test pointer hygiene under interleaved inputs.
- #4easyfoundational
4. Remove Duplicates from Sorted Array
Dedupe a sorted array in place — Glassdoor uses this to test two-pointer reasoning on the kind of stream they dedupe in salary reports.
- #5easyfoundational
5. Remove Element
Remove all instances of a value in place — Glassdoor uses this to confirm you can think about partition pointers without a temp array.
- #6easyfoundational
6. Search Insert Position
Find the index where a target should be inserted in a sorted array — Glassdoor uses this to grade binary-search precision under boundary conditions.
- #7easyfoundational
7. Plus One
Increment a digit array by one — Glassdoor uses this to grade carry-handling cleanliness and how you deal with the leading-digit edge case.
- #8easyfoundational
8. Merge Sorted Array
Merge nums2 into nums1 in place — Glassdoor uses this to test reverse-pointer thinking on a problem with hidden cleverness.
- #9easyfoundational
9. Binary Tree Inorder Traversal
Return the inorder traversal of a binary tree — Glassdoor uses this to gauge tree recursion fluency, then probes the iterative version.
- #10easyfoundational
10. Same Tree
Determine whether two binary trees are identical in shape and values — Glassdoor uses this to grade recursive base-case discipline.
- #11easyfoundational
11. Symmetric Tree
Check if a binary tree is a mirror of itself — Glassdoor uses this to test paired-recursion reasoning.
- #12easyfoundational
12. Maximum Depth of Binary Tree
Return the maximum depth of a binary tree — Glassdoor uses this as a quick warm-up to grade your recursion height intuition.
- #13easyfoundational
13. Balanced Binary Tree
Return whether a binary tree is height-balanced — Glassdoor uses this to test whether you can fold height + balance into one O(n) post-order traversal.
- #14easyfoundational
14. Minimum Depth of Binary Tree
Find the shortest path from root to any leaf — Glassdoor uses this to grade whether you correctly handle one-sided trees (often missed).