Blind 75 Leetcode problems with detailed and optimized solutions

Blind 75 Leetcode problems is a comprehensive list of problems which has helped developers worldwide to crack their technical interviews including that of Google, Amazon, Microsoft, Meta (formerly Facebook) and so on.

This list was created by Yangshun, an ex-Meta (formerly Facebook) Staff Engineer.

Leetcode has thousands of questions and it is very confusing where to start and how to proceed.

This list of 75 Leetcode questions commonly called as Blind 75 is a tried and tested list with many testimonials around it.

Let's look at the questions that are part of Blind 75 list.

Blind 75 Leetcode Questions

No.SolutionLink
1Contains DuplicateArrays & HashingEasy
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2Valid AnagramStringsEasy
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3Two SumArrays & HashingMedium
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4Group AnagramsStringsMedium
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5Top K Frequent ElementsHeapMedium
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6Encode and Decode StringsStringsMedium
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7Product of Array Except SelfArrays & HashingMedium
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8Longest Consecutive SequenceArrays & HashingMedium
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9Valid PalindromeStringsEasy
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103SumArrays & HashingMedium
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11Container With Most WaterTwo PointersMedium
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12Best Time to Buy and Sell StockDynamic ProgrammingEasy
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13Longest Substring Without Repeating CharactersSliding WindowMedium
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14Longest Repeating Character ReplacementSliding WindowMedium
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15Minimum Window SubstringSliding WindowHard
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16Valid ParenthesesStackEasy
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17Find Minimum in Rotated Sorted ArrayBinary SearchMedium
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18Search in Rotated Sorted ArrayBinary SearchMedium
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19Reverse Linked ListLinked ListEasy
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20Merge Two Sorted ListsLinked ListEasy
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21Reorder ListLinked ListMedium
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22Remove Nth Node From End of ListLinked ListMedium
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23Linked List CycleLinked ListMedium
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24Merge K Sorted ListsLinked ListHard
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25Invert Binary TreeTreeEasy
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26Maximum Depth of Binary TreeTreeEasy
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27Same TreeTreeEasy
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28Subtree of Another TreeTreeMedium
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29Lowest Common Ancestor of a Binary Search TreeTreeMedium
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30Binary Tree Level Order TraversalTreeMedium
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31Validate Binary Search TreeTreeMedium
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32Kth Smallest Element in a BSTTreeMedium
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33Construct Binary Tree from Preorder and Inorder TraversalTreeMedium
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34Binary Tree Maximum Path SumTreeHard
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35Serialize and Deserialize Binary TreeTreeMedium
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36Find Median from Data StreamDesignHard
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37Combination SumBacktrackingMedium
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38Word SearchBacktrackingMedium
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39Implement Trie (Prefix Tree)DesignMedium
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40Design Add and Search Words Data StructureDesignMedium
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41Word Search IIBacktrackingHard
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42Number of IslandsGraphMedium
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43Clone GraphGraphMedium
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44Pacific Atlantic Water FlowGraphMedium
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45Course ScheduleGraphMedium
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46Graph Valid TreeGraphMedium
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47Number of Connected Components in an Undirected GraphGraphMedium
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48Alien DictionaryGraphHard
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49Climbing StairsDynamic ProgrammingEasy
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50House RobberDynamic ProgrammingMedium
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51House Robber IIDynamic ProgrammingMedium
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52Longest Palindromic SubstringDynamic ProgrammingMedium
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53Palindromic SubstringsDynamic ProgrammingMedium
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54Decode WaysDynamic ProgrammingMedium
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55Coin ChangeDynamic ProgrammingMedium
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56Maximum Product SubarrayDynamic ProgrammingMedium
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57Word BreakDynamic ProgrammingMedium
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58Longest Increasing SubsequenceDynamic ProgrammingMedium
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59Unique PathsDynamic ProgrammingMedium
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60Longest Common SubsequenceDynamic ProgrammingMedium
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61Maximum SubarrayDynamic ProgrammingEasy
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62Jump GameDynamic ProgrammingMedium
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63Insert IntervalArray & IntervalsMedium
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64Merge IntervalsArray & IntervalsMedium
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65Non-overlapping IntervalsArray & IntervalsMedium
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66Meeting RoomsArray & IntervalsEasy
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67Meeting Rooms IIArray & IntervalsMedium
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68Rotate ImageMatrixMedium
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69Spiral MatrixMatrixMedium
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70Set Matrix ZeroesMatrixMedium
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71Number of 1 BitsBit ManipulationEasy
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72Counting BitsBit ManipulationEasy
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73Reverse BitsBit ManipulationEasy
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74Missing NumberBit ManipulationEasy
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75Sum of Two IntegersBit ManipulationEasy
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Frequently asked questions (FAQ) on Blind 75 Leetcode

1. Is solving the Blind 75 LeetCode problems enough to crack any technical interview?

The Blind 75 list covers a broad range of topics, patterns, and concepts that are essential for technical interviews.

However, if you have additional time, it’s beneficial to tackle more problems beyond this list to further solidify your problem-solving skills.

2. How should I get started?

Begin by tackling easier problems across various topics to build confidence.

Gradually progress to medium difficulty questions, and eventually work on harder problems.

This approach will help you understand different problem types and develop a well-rounded skill set.

3. How long will it take to complete all the problems?

For beginners dedicating 3-4 hours per day, you should be well-positioned within approximately 3 months.

Remember to pace yourself, retain the information you learn, and most importantly, enjoy the problem-solving process.

4. What coding language should I use for interviews?

Choose the programming language you are most comfortable with.

Interviewers are more interested in your problem-solving skills and logic rather than the specific syntax of the language you use.

5. What if I still have doubts after checking the solution?

If you have lingering doubts, consider reviewing the LeetCode discussion forums or other resources.

Engaging with the community can provide additional insights and clarifications.

If you need further help, reach out to us.

6. I'm really demotivated. I dont know how to start. Can you help me ?

Sure. We've got you covered. Book a 1:1 call with us, and we will make a personalized plan to help you out.

7. What should I do after preparing?

Once you feel prepared, update your resume and start applying for jobs.

Please do checkout our comprehensive guide - Cracking Tech Interview : From Resume Preparation to Offer Negotiation

If you need personalized assistance or further guidance, don’t hesitate to reach out to us for support.

8. I really like your content. How can I help you ?

If you notice any areas where the answers could be clearer or more accurate, feel free to suggest improvements.

And we would be more than happy if you share it across for others to benefit as well.

9. My question is not part of FAQ. What can I do ?

Write to us at admin@dotnetinterviews.com and we will help you !

Conclusion

Incorporating the Blind 75 Leetcode problems into your study routine can provide a solid foundation for tackling technical interviews.

By focusing on these carefully selected problems, you’ll develop a deeper understanding of key concepts and problem-solving techniques.

Remember, while this list is an excellent resource, supplementing it with additional practice and real-world problem-solving will further enhance your readiness for interviews.

Stay dedicated, keep practicing, and you'll be well on your way to acing your technical interviews.

All the very best with your preparation ! We look forward to hearing back from you.

If you're a .NET developer, also checkout Ultimate Guide to .NET Interview Preparation