1Serialize and Deserialize Binary TreeHardStringTreeDepth-First Search
Solve → 2Split Message Based on LimitHardStringEnumeration
Solve → 3Serialize and Deserialize Binary TreeHardStringTreeDepth-First Search
Solve → 4Shortest PalindromeHardStringRolling HashString Matching
Solve → 5String to Integer (atoi)MediumString
Solve → 6Regular Expression MatchingHardStringDynamic ProgrammingRecursion
Solve → 7Valid ParenthesesEasyStringStack
Solve → 8Longest Valid ParenthesesHardStringDynamic ProgrammingStack
Solve → 9Decode WaysMediumStringDynamic Programming
Solve → 10Simplify PathMediumStringStack
Solve → 11Generate ParenthesesMediumStringDynamic ProgrammingBacktracking
Solve → 12Longest Palindromic SubsequenceMediumStringDynamic Programming
Solve → 13Calculate Digit Sum of a StringEasyStringSimulation
Solve → 14Design Search Autocomplete SystemHardStringDepth-First SearchDesign
Solve → 15Count Palindromic SubsequencesHardStringDynamic Programming
Solve → 16Count Different Palindromic SubsequencesHardStringDynamic Programming
Solve → 17Number of Distinct Substrings in a StringMediumStringTrieRolling Hash
Solve → 18Repeated String MatchMediumStringString Matching
Solve → 19Serialize and Deserialize Binary TreeHardStringTreeDepth-First Search
Solve → 20Split Message Based on LimitHardStringEnumeration
Solve → 21Decode WaysMediumStringDynamic Programming
Solve → 22String to Integer (atoi)MediumString
Solve → 23Regular Expression MatchingHardStringDynamic ProgrammingRecursion
Solve → 24Generate ParenthesesMediumStringDynamic ProgrammingBacktracking
Solve → 25Longest Palindromic SubsequenceMediumStringDynamic Programming
Solve → 26Calculate Digit Sum of a StringEasyStringSimulation
Solve → 27Longest Valid ParenthesesHardStringDynamic ProgrammingStack
Solve → 28Shortest PalindromeHardStringRolling HashString Matching
Solve → 29Valid ParenthesesEasyStringStack
Solve → 30Design Search Autocomplete SystemHardStringDepth-First SearchDesign
Solve → 31Simplify PathMediumStringStack
Solve → 32Freedom TrailHardStringDynamic ProgrammingDepth-First Search
Solve → 33Count Different Palindromic SubsequencesHardStringDynamic Programming
Solve → 34Count Palindromic SubsequencesHardStringDynamic Programming
Solve → 35Number of Distinct Substrings in a StringMediumStringTrieRolling Hash
Solve → 36Repeated String MatchMediumStringString Matching
Solve →