358.Rearrange String k Distance Apart
HardCountingGreedyHash Table39.9% acceptance4 companiesPremium elsewhere, free hereVideo
Hard · With video · 18 results
992.Subarrays with K Different Integers
HardArrayCountingHash Table69.0% acceptance18 companiesVideo
1121.Divide Array Into Increasing Sequences
HardArrayCounting65.4% acceptance1 companyPremium elsewhere, free hereVideo
1819.Number of Different Subsequences GCDs
HardArrayCountingMath47.2% acceptance2 companiesVideo
1857.Largest Color Value in a Directed Graph
HardCountingDynamic ProgrammingGraph57.3% acceptance5 companiesVideo
2014.Longest Subsequence Repeated k Times
HardBacktrackingCountingEnumeration71.3% acceptance3 companiesVideo
2025.Maximum Number of Ways to Partition an Array
HardArrayCountingEnumeration36.2% acceptance2 companiesVideo
2416.Sum of Prefix Scores of Strings
HardArrayCountingString60.6% acceptance3 companiesVideo
2499.Minimum Total Cost to Make Arrays Unequal
HardArrayCountingGreedy41.3% acceptance1 companyVideo
2514.Count Anagrams
HardCombinatoricsCountingHash Table38.4% acceptance1 companyVideo
2547.Minimum Cost to Split an Array
HardArrayCountingDynamic Programming45.4% acceptance1 companyVideo
3267.Count Almost Equal Pairs II
HardArrayCountingEnumeration27.7% acceptanceVideo
3279.Maximum Total Area Occupied by Pistons
HardArrayCountingHash Table41.3% acceptancePremium elsewhere, free hereVideo
3312.Sorted GCD Pair Queries
HardArrayBinary SearchCombinatorics58.4% acceptance1 companyVideo
3337.Total Characters in String After Transformations II
HardCountingDynamic ProgrammingHash Table58.0% acceptance2 companiesVideo
3518.Smallest Palindromic Rearrangement II
HardCombinatoricsCountingHash Table44.3% acceptanceVideo
3859.Count Subarrays With K Distinct Integers
HardArrayCountingHash Table21.0% acceptanceVideo
4007.Widest Possible Fence
HardArrayCountingEnumeration16.9% acceptanceVideo
Showing 1–18 of 18
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.