Sigmoid LeetCode Interview Questions
Sigmoid has asked 14 distinct LeetCode questions across all recorded interviews: 4 easy, 9 medium and 1 hard. The questions reported most often are Binary Tree Zigzag Level Order Traversal, Best Time to Buy and Sell Stock and Product of Array Except Self. 1 of them was reported in interviews from the Last 6 Months window. Every question links straight to LeetCode, and the list can be filtered by difficulty and topic or sorted by how often the question comes up.
| # | Problem | Difficulty | Frequency | Acceptance | |
|---|---|---|---|---|---|
| 1 | Binary Tree Zigzag Level Order Traversal | Medium | 100 | 0.6% | |
| 2 | Best Time to Buy and Sell Stock | Easy | 92 | 0.6% | |
| 3 | Product of Array Except Self | Medium | 80 | 0.7% | |
| 4 | Reverse Nodes in k-Group | Hard | 80 | 0.7% | |
| 5 | Boats to Save People | Medium | 80 | 0.6% | |
| 6 | Valid Parentheses | Easy | 80 | 0.4% | |
| 7 | Longest Substring Without Repeating Characters | Medium | 80 | 0.4% | |
| 8 | Min Stack | Medium | 80 | 0.6% | |
| 9 | Best Time to Buy and Sell Stock II | Medium | 80 | 0.7% | |
| 10 | Move Zeroes | Easy | 80 | 0.6% | |
| 11 | Group Anagrams | Medium | 80 | 0.7% | |
| 12 | Longest Common Prefix | Easy | 80 | 0.5% | |
| 13 | Coin Change | Medium | 80 | 0.5% | |
| 14 | Rotting Oranges | Medium | 80 | 0.6% |
Where this data comes from
These questions come from the public leetcode-company-wise-problems data set, which collects interview reports from candidates. They are community-reported rather than published by Sigmoid, so treat the list as a strong signal of what gets asked, not an official or exhaustive syllabus. Last refreshed .
How to read this list
The tabs at the top split the questions by how recently people said they were asked in interviews. "Last 30 Days" is the past month, "Last 3 Months" is the past quarter, and so on. "All Time" is every question on record for this company.
Frequency is a score from 0 to 100 for how often a question showed up in that time window. A higher number means it came up more often, so the list starts with the most common questions first. It is a relative popularity signal within Sigmoid's questions, not a probability that you will be asked it. Acceptance is LeetCode's own share of submissions that pass for that problem, across all users, not something specific to Sigmoid. Click any question to open it on LeetCode.