Sean Prashad's LeetCode Patterns is a free, open-source list of LeetCode problems grouped by the pattern each one teaches, with company tags on most problems. It was inspired by Grokking the Coding Interview and adds problems from Blind 75. This page covers its size, how it is organized, what the company tags mean, and a study order that turns the list into patterns you recognize. For pattern explanations, see our LeetCode patterns guide.
What is on the list
Counts were read from each list's own site data on November 9, 2026. Lists are edited from time to time, so numbers can drift.
| LeetCode Patterns | |
|---|---|
| Problems | 179 |
| Easy / Medium / Hard | 41 / 112 / 26 |
| LeetCode Premium problems | 13 |
| Distinct pattern and topic tags | 75 |
| Problems with company tags | 165 of 179, across 113 companies |
How it is organized
The list is one filterable table. Each problem carries one or more tags, the most common being arrays, strings, hash tables, sorting, depth-first search, dynamic programming and two pointers. A 'Helpful Tips' panel maps clues in a problem statement to techniques in seven groups: arrays and strings, subarrays and sequences, trees and graphs, linked lists and stacks, sorting and intervals, optimization, and general.
What the company tags tell you
- The most frequent companies are Google, Amazon, Bloomberg, Microsoft and Meta.
- Each tag shows a frequency number, refreshed by automated updates; the site does not say where the company data comes from, so treat it as a rough signal.
- Use the tags to choose between problems of the same pattern, not to predict your exact question.
A study order that works
- Read the Helpful Tips panel first, so you know which clue points to which pattern.
- Filter by one pattern at a time, starting with arrays, two pointers and sliding window.
- Do the easy problems in a pattern, then the mediums, and stop when you can name the pattern within two minutes of reading a new problem.
- Move to trees and graphs, then dynamic programming.
- Finish with mixed sets filtered by your target company, solved under time limits.
Our array and string patterns guide explains the first patterns with templates.
How it compares with other lists
LeetCode Patterns is larger than Blind 75 guide (75 problems) and organized by technique rather than by topic. If you want a fixed order with video explanations, the NeetCode 150 roadmap suits better; if you want to learn to recognize patterns and pick problems by company, this list is the better tool.
Turning a list into interview skill
Any list only helps if the practice transfers to problems you have not seen. These habits make the difference:
- Time-box every attempt: about 25 minutes for a medium before you read a solution.
- Keep a log with one line per problem: the pattern, the key idea and the complexity.
- Redo failed problems after three days, a week and three weeks, without looking at your old code.
- Explain your approach out loud before and while you code, as you would to an interviewer.
- In the last two weeks, switch to unseen problems without topic labels.
The patterns most lists are built on are explained in array and string patterns and tree, graph and recursion patterns.
Where CoPilot Interview fits
Finishing a list is not the same as passing an interview: interviewers score how you explain your approach, your trade-offs and your complexity out loud. CoPilot Interview is an AI interview assistant; its free AI mock interview asks coding questions, listens to your spoken explanation and scores it out of ten with a model answer, which is the part a problem list cannot train. The free plan gives 15 minutes a day of live help in sessions of up to 15 minutes, with AI mock interviews included. Online assessments and live coding rounds usually forbid outside help, so practice now and follow your employer's rules on the day.
Disclosure: CoPilot Interview is our product, so weigh what we say about it accordingly.
Frequently asked questions
How many problems are in Sean Prashad's LeetCode Patterns?
179 as of November 2026: 41 easy, 112 medium and 26 hard, with 13 that need LeetCode Premium.
Is LeetCode Patterns free?
Yes. It is a free, open-source project; a few of the linked problems need LeetCode Premium.
Is it better than Blind 75?
It is bigger and organized by pattern with company tags. Blind 75 is shorter and fixed. Many people do Blind 75 first and use LeetCode Patterns to fill gaps.
Where do the company tags come from?
The site does not say. Treat them as a rough signal of frequency, not a prediction.
Practice this interview before the real one
The AI mock interview builds questions from your resume and the job description, reads them aloud and scores each spoken answer out of 10. Included on the free plan.
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