2060.Check if an Original String Exists Given Two Encoded Strings
HardDynamic ProgrammingString43.6% acceptance2 companiesVideo
Hard · 177 results
2147.Number of Ways to Divide a Long Corridor
HardDynamic ProgrammingMathString54.6% acceptance3 companiesVideo
2156.Find Substring With Given Hash Value
HardHash FunctionRolling HashSliding Window27.3% acceptance1 companyVideo
2157.Groups of Strings
HardBit ManipulationStringUnion Find28.2% acceptance1 companyVideo
2167.Minimum Time to Remove All Cars Containing Illegal Goods
HardDynamic ProgrammingString42.2% acceptance1 companyVideo
2193.Minimum Number of Moves to Make Palindrome
HardBinary Indexed TreeGreedyString52.7% acceptance5 companiesVideo
2209.Minimum White Tiles After Covering With Carpets
HardDynamic ProgrammingPrefix SumString39.3% acceptance1 companyVideo
2213.Longest Substring of One Repeating Character
HardArrayOrdered SetSegment Tree65.8% acceptance1 companyVideo
2223.Sum of Scores of Built Strings
HardBinary SearchHash FunctionRolling Hash51.0% acceptance1 companyVideo
2227.Encrypt and Decrypt Strings
HardArrayDesignHash Table38.8% acceptance3 companiesVideo
2246.Longest Path With Different Adjacent Characters
HardArrayDepth-First SearchGraph54.2% acceptance5 companiesVideo
2262.Total Appeal of A String
HardDynamic ProgrammingHash TableString56.4% acceptance2 companiesVideo
2296.Design a Text Editor
HardDesignDoubly-Linked ListLinked List52.1% acceptance10 companiesVideo
2301.Match Substring After Replacement
HardArrayHash TableString43.9% acceptance1 companyVideo
2306.Naming a Company
HardArrayBit ManipulationEnumeration46.4% acceptance1 companyVideo
2416.Sum of Prefix Scores of Strings
HardArrayCountingString60.6% acceptance3 companiesVideo
2430.Maximum Deletions on a String
HardDynamic ProgrammingHash FunctionRolling Hash36.4% acceptance1 companyVideo
2468.Split Message Based on Limit
HardBinary SearchString42.1% acceptance5 companiesVideo
2472.Maximum Number of Non-overlapping Palindrome Substrings
HardDynamic ProgrammingGreedyString60.9% acceptance5 companiesVideo
2478.Number of Beautiful Partitions
HardDynamic ProgrammingString33.5% acceptance1 companyVideo
2484.Count Palindromic Subsequences
HardDynamic ProgrammingString41.7% acceptance11 companiesVideo
2514.Count Anagrams
HardCombinatoricsCountingHash Table38.4% acceptance1 companyVideo
2565.Subsequence With the Minimum Score
HardBinary SearchStringTwo Pointers33.8% acceptance1 companyVideo
2573.Find the String with LCP
HardArrayDynamic ProgrammingGreedy63.3% acceptance1 companyVideo
2663.Lexicographically Smallest Beautiful String
HardGreedyString37.9% acceptance2 companiesVideo
2719.Count of Integers
HardDynamic ProgrammingMathString38.9% acceptance2 companiesVideo
2781.Length of the Longest Valid Substring
HardArrayHash TableSliding Window38.3% acceptance3 companiesVideo
2801.Count Stepping Numbers in Range
HardDynamic ProgrammingString28.7% acceptance2 companiesVideo
2842.Count K-Subsequences of a String With Maximum Beauty
HardCombinatoricsGreedyHash Table30.2% acceptance1 companyVideo
2851.String Transformation
HardDynamic ProgrammingMathString27.4% acceptance3 companiesVideo
2868.The Wording Game
HardArrayGame TheoryGreedy53.6% acceptancePremium elsewhere, free here
2911.Minimum Changes to Make K Semi-palindromes
HardDynamic ProgrammingStringTwo Pointers35.3% acceptanceVideo
2949.Count Beautiful Substrings II
HardHash TableMathNumber Theory27.5% acceptance1 companyVideo
2953.Count Complete Substrings
HardHash TableSliding WindowString31.3% acceptance1 companyVideo
2977.Minimum Cost to Convert String II
HardArrayDynamic ProgrammingGraph59.1% acceptance4 companiesVideo
2983.Palindrome Rearrangement Queries
HardHash TablePrefix SumString24.4% acceptanceVideo
2999.Count the Number of Powerful Integers
HardDynamic ProgrammingMathString46.3% acceptance5 companiesVideo
3003.Maximize the Number of Partitions After Operations
HardBit ManipulationBitmaskDynamic Programming53.5% acceptance1 companyVideo
3008.Find Beautiful Indices in the Given Array II
HardBinary SearchHash FunctionRolling Hash28.3% acceptance3 companiesVideo
3031.Minimum Time to Revert Word to Initial State II
HardHash FunctionRolling HashString35.1% acceptance1 companyVideo
3045.Count Prefix and Suffix Pairs II
HardArrayHash FunctionRolling Hash28.2% acceptance4 companiesVideo
3088.Make String Anti-palindrome
HardCounting SortGreedySorting46.6% acceptance1 companyPremium elsewhere, free hereVideo
3093.Longest Common Suffix Queries
HardArrayStringTrie52.8% acceptance2 companiesVideo
3104.Find Longest Self-Contained Substring
HardBinary SearchHash TablePrefix Sum58.6% acceptance1 companyPremium elsewhere, free hereVideo
3213.Construct String with Minimum Cost
HardArrayDynamic ProgrammingString19.0% acceptance1 companyVideo
3260.Find the Largest Palindrome Divisible by K
HardDynamic ProgrammingGreedyMath17.0% acceptance2 companiesVideo
3261.Count Substrings That Satisfy K-Constraint II
HardArrayBinary SearchPrefix Sum24.1% acceptanceVideo
3279.Maximum Total Area Occupied by Pistons
HardArrayCountingHash Table41.3% acceptancePremium elsewhere, free hereVideo
3292.Minimum Number of Valid Strings to Form Target II
HardArrayBinary SearchDynamic Programming21.1% acceptanceVideo
3298.Count Substrings That Can Be Rearranged to Contain a String II
HardHash TableSliding WindowString55.2% acceptanceVideo
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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.