3337.Total Characters in String After Transformations II
HardCountingDynamic ProgrammingHash Table58.0% acceptance2 companiesVideo
Hard · 119 results
3351.Sum of Good Subsequences
HardArrayDynamic ProgrammingHash Table30.9% acceptance1 companyVideo
3369.Design an Array Statistics Tracker
HardBinary SearchHash TableQueue35.7% acceptance1 companyPremium elsewhere, free hereVideo
3378.Count Connected Components in LCM Graph
HardArrayHash TableMath31.3% acceptanceVideo
3510.Minimum Pair Removal to Sort Array II
HardArrayDoubly-Linked ListHash Table39.1% acceptance3 companiesVideo
3518.Smallest Palindromic Rearrangement II
HardCombinatoricsCountingHash Table44.3% acceptanceVideo
3548.Equal Sum Grid Partition II
HardArrayEnumerationHash Table39.5% acceptance2 companiesVideo
3625.Count Number of Trapezoids II
HardArrayGeometryHash Table40.0% acceptance2 companiesVideo
3721.Longest Balanced Subarray II
HardArrayDivide and ConquerHash Table33.7% acceptance2 companiesVideo
3729.Count Distinct Subarrays Divisible by K in Sorted Array
HardArrayHash TablePrefix Sum27.4% acceptanceVideo
3739.Count Subarrays With Majority Element II
HardArrayDivide and ConquerHash Table65.2% acceptance2 companiesVideo
3749.Evaluate Valid Expressions
HardDivide and ConquerHash TableMath69.2% acceptancePremium elsewhere, free here
3816.Lexicographically Smallest String After Deleting Duplicate Characters
HardGreedyHash TableMonotonic Stack20.9% acceptance2 companiesVideo
3859.Count Subarrays With K Distinct Integers
HardArrayCountingHash Table21.0% acceptanceVideo
3873.Maximum Points Activated with One Addition
HardArrayHash TableUnion Find42.8% acceptanceVideo
3934.Smallest Unique Subarray
HardArrayBinary SearchHash Function39.7% acceptanceVideo
3962.Maximum Subarray Sum After at Most K Swaps
HardArrayBinary Indexed TreeGreedy14.2% acceptance1 companyVideo
4007.Widest Possible Fence
HardArrayCountingEnumeration16.9% acceptanceVideo
4064.Longest Subarray Divisible by K with At Most One Negation II
HardArrayBinary SearchHash Table24.7% acceptanceVideo
Showing 101–119 of 119
How to use these solutions
Each solution breaks the problem into approaches, usually from brute force to the best one, and explains why each works. Code comes in Python, Java, C++ and other languages. Knowing why an approach works matters more in an interview than remembering the code.
- Try the problem first. Give it at least 20 minutes before you open the solution.
- Read every approach. The brute force shows you the problem; the faster ones show the pattern.
- Check the complexity. Note the time and space of each approach and what makes the difference.
- Write it yourself. Close the solution and code it from memory in the editor.
- Come back in a week. Solving it again later is what makes the pattern stick.