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String

439 questions

1Valid ParenthesesEasy
StringStack
Solve →
2String to Integer (atoi)Medium
String
Solve →
3Generate ParenthesesMedium
StringDynamic ProgrammingBacktracking
Solve →
4Regular Expression MatchingHard
StringDynamic ProgrammingRecursion
Solve →
5Palindrome Partitioning IIHard
StringDynamic Programming
Solve →
6Length of Last WordEasy
String
Solve →
7Valid ParenthesesEasy
StringStack
Solve →
8Generate ParenthesesMedium
StringDynamic ProgrammingBacktracking
Solve →
9String to Integer (atoi)Medium
String
Solve →
10Rotate StringEasy
StringString Matching
Solve →
11Regular Expression MatchingHard
StringDynamic ProgrammingRecursion
Solve →
12Length of Last WordEasy
String
Solve →
13Zigzag ConversionMedium
String
Solve →
14Decode StringMedium
StringStackRecursion
Solve →
15Longest Valid ParenthesesHard
StringDynamic ProgrammingStack
Solve →
16Lexicographically Smallest Generated StringHard
StringGreedyString Matching
Solve →
17Remove All Adjacent Duplicates In StringEasy
StringStack
Solve →
18Edit DistanceMedium
StringDynamic Programming
Solve →
19Palindrome PartitioningMedium
StringDynamic ProgrammingBacktracking
Solve →
20Minimum Distance to Type a Word Using Two FingersHard
StringDynamic Programming
Solve →
21Valid Parenthesis StringMedium
StringDynamic ProgrammingStack
Solve →
22Palindrome Partitioning IIHard
StringDynamic Programming
Solve →
23Wildcard MatchingHard
StringDynamic ProgrammingGreedy
Solve →
24Design Search Autocomplete SystemHard
StringDepth-First SearchDesign
Solve →
25Check if Strings Can be Made Equal With Operations IEasy
String
Solve →
26Minimum Add to Make Parentheses ValidMedium
StringStackGreedy
Solve →
27Robot Return to OriginEasy
StringSimulation
Solve →
28Serialize and Deserialize Binary TreeHard
StringTreeDepth-First Search
Solve →
29Simplify PathMedium
StringStack
Solve →
30Count and SayMedium
String
Solve →
31Valid ParenthesesEasy
StringStack
Solve →
32Generate ParenthesesMedium
StringDynamic ProgrammingBacktracking
Solve →
33Decode StringMedium
StringStackRecursion
Solve →
34Regular Expression MatchingHard
StringDynamic ProgrammingRecursion
Solve →
35Length of Last WordEasy
String
Solve →
36String to Integer (atoi)Medium
String
Solve →
37Edit DistanceMedium
StringDynamic Programming
Solve →
38Longest Valid ParenthesesHard
StringDynamic ProgrammingStack
Solve →
39Zigzag ConversionMedium
String
Solve →
40Palindrome PartitioningMedium
StringDynamic ProgrammingBacktracking
Solve →
41Rotate StringEasy
StringString Matching
Solve →
42Wildcard MatchingHard
StringDynamic ProgrammingGreedy
Solve →
43Simplify PathMedium
StringStack
Solve →
44Longest Common SubsequenceMedium
StringDynamic Programming
Solve →
45Valid Parenthesis StringMedium
StringDynamic ProgrammingStack
Solve →
46Remove All Adjacent Duplicates In StringEasy
StringStack
Solve →
47Repeated Substring PatternEasy
StringString Matching
Solve →
48Special Binary StringHard
StringDivide and ConquerSorting
Solve →
49Find Kth Bit in Nth Binary StringMedium
StringRecursionSimulation
Solve →
50The k-th Lexicographical String of All Happy Strings of Length nMedium
StringBacktracking
Solve →
51Remove K DigitsMedium
StringStackGreedy
Solve →
52Design Search Autocomplete SystemHard
StringDepth-First SearchDesign
Solve →
53Count and SayMedium
String
Solve →
54Longest Duplicate SubstringHard
StringBinary SearchSliding Window
Solve →
55Interleaving StringMedium
StringDynamic Programming
Solve →
56Binary Tree PathsEasy
StringBacktrackingTree
Solve →
57Minimum Deletions to Make String BalancedMedium
StringDynamic ProgrammingStack
Solve →
58Lexicographically Smallest Generated StringHard
StringGreedyString Matching
Solve →
59Serialize and Deserialize Binary TreeHard
StringTreeDepth-First Search
Solve →
60Remove Outermost ParenthesesEasy
StringStack
Solve →
61Minimum Add to Make Parentheses ValidMedium
StringStackGreedy
Solve →
62Score of a StringEasy
String
Solve →
63Number of Steps to Reduce a Number in Binary Representation to OneMedium
StringBit ManipulationSimulation
Solve →
64Partitioning Into Minimum Number Of Deci-Binary NumbersMedium
StringGreedy
Solve →
65Check if Strings Can be Made Equal With Operations IEasy
String
Solve →
66Minimum Distance to Type a Word Using Two FingersHard
StringDynamic Programming
Solve →
67Decode WaysMedium
StringDynamic Programming
Solve →
68Longest Palindromic SubsequenceMedium
StringDynamic Programming
Solve →
69Palindrome Partitioning IIHard
StringDynamic Programming
Solve →
70Shortest PalindromeHard
StringRolling HashString Matching
Solve →
71Sorting the SentenceEasy
StringSorting
Solve →
72Check if Binary String Has at Most One Segment of OnesEasy
String
Solve →
73Minimum Number of Flips to Make the Binary String AlternatingMedium
StringDynamic ProgrammingSliding Window
Solve →
74Remove Duplicate LettersMedium
StringStackGreedy
Solve →
75Score of ParenthesesMedium
StringStack
Solve →
76Decode the Slanted CiphertextMedium
StringSimulation
Solve →
77Furthest Point From OriginEasy
StringCounting
Solve →
78Robot Return to OriginEasy
StringSimulation
Solve →
79Validate IP AddressMedium
String
Solve →
80Scramble StringHard
StringDynamic Programming
Solve →
81Maximum Nesting Depth of the ParenthesesEasy
StringStack
Solve →
82Remove All Adjacent Duplicates in String IIMedium
StringStack
Solve →
83Make The String GreatEasy
StringStack
Solve →
84Valid ParenthesesEasy
StringStack
Solve →
85Generate ParenthesesMedium
StringDynamic ProgrammingBacktracking
Solve →
86Decode StringMedium
StringStackRecursion
Solve →
87Zigzag ConversionMedium
String
Solve →
88Regular Expression MatchingHard
StringDynamic ProgrammingRecursion
Solve →
89Palindrome PartitioningMedium
StringDynamic ProgrammingBacktracking
Solve →
90Remove K DigitsMedium
StringStackGreedy
Solve →
91Edit DistanceMedium
StringDynamic Programming
Solve →
92Length of Last WordEasy
String
Solve →
93Wildcard MatchingHard
StringDynamic ProgrammingGreedy
Solve →
94String to Integer (atoi)Medium
String
Solve →
95Longest Common SubsequenceMedium
StringDynamic Programming
Solve →
96Rotate StringEasy
StringString Matching
Solve →
97Longest Valid ParenthesesHard
StringDynamic ProgrammingStack
Solve →
98Shortest PalindromeHard
StringRolling HashString Matching
Solve →
99Simplify PathMedium
StringStack
Solve →
100Serialize and Deserialize Binary TreeHard
StringTreeDepth-First Search
Solve →
101Lexicographically Smallest Beautiful StringHard
StringGreedy
Solve →
102Count and SayMedium
String
Solve →
103Decode WaysMedium
StringDynamic Programming
Solve →
104Minimum Add to Make Parentheses ValidMedium
StringStackGreedy
Solve →
105Remove Duplicate LettersMedium
StringStackGreedy
Solve →
106Shortest Common SupersequenceHard
StringDynamic Programming
Solve →
107Distinct SubsequencesHard
StringDynamic Programming
Solve →
108Repeated Substring PatternEasy
StringString Matching
Solve →
109Valid Parenthesis StringMedium
StringDynamic ProgrammingStack
Solve →
110Longest Palindromic SubsequenceMedium
StringDynamic Programming
Solve →
111Remove Outermost ParenthesesEasy
StringStack
Solve →
112Score of a StringEasy
String
Solve →
113Longest Duplicate SubstringHard
StringBinary SearchSliding Window
Solve →
114Maximum Score After Splitting a StringEasy
StringPrefix Sum
Solve →
115Defanging an IP AddressEasy
String
Solve →
116Interleaving StringMedium
StringDynamic Programming
Solve →
117Binary Tree PathsEasy
StringBacktrackingTree
Solve →
118Repeated String MatchMedium
StringString Matching
Solve →
119Minimum Remove to Make Valid ParenthesesMedium
StringStack
Solve →
120Design Add and Search Words Data StructureMedium
StringDepth-First SearchDesign
Solve →
121Remove All Occurrences of a SubstringMedium
StringStackSimulation
Solve →
122Clear DigitsEasy
StringStackSimulation
Solve →
123Restore IP AddressesMedium
StringBacktracking
Solve →
124Longest Absolute File PathMedium
StringStackDepth-First Search
Solve →
125Design Search Autocomplete SystemHard
StringDepth-First SearchDesign
Solve →
126Maximum Score From Removing SubstringsMedium
StringStackGreedy
Solve →
127Minimum Deletions to Make String BalancedMedium
StringDynamic ProgrammingStack
Solve →
128Longest Palindromic Subsequence After at Most K OperationsMedium
StringDynamic Programming
Solve →
129Parsing A Boolean ExpressionHard
StringStackRecursion
Solve →
130Detect CapitalEasy
String
Solve →
131Remove All Adjacent Duplicates In StringEasy
StringStack
Solve →
132Count the Number of Substrings With Dominant OnesMedium
StringEnumeration
Solve →
133Recover a Tree From Preorder TraversalHard
StringTreeDepth-First Search
Solve →
134Make The String GreatEasy
StringStack
Solve →
135Robot Return to OriginEasy
StringSimulation
Solve →
136Maximum Number of Operations to Move Ones to the EndMedium
StringGreedyCounting
Solve →
137Find the Original Typed String IIHard
StringDynamic ProgrammingPrefix Sum
Solve →
138Palindrome Partitioning IIHard
StringDynamic Programming
Solve →
139Scramble StringHard
StringDynamic Programming
Solve →
140Serialize and Deserialize N-ary TreeHard
StringTreeDepth-First Search
Solve →
141Delete Operation for Two StringsMedium
StringDynamic Programming
Solve →
142String Compression IIIMedium
String
Solve →
143Additive NumberMedium
StringBacktracking
Solve →
144The k-th Lexicographical String of All Happy Strings of Length nMedium
StringBacktracking
Solve →
145Valid NumberHard
String
Solve →
146Largest 3-Same-Digit Number in StringEasy
String
Solve →
147Remove Invalid ParenthesesHard
StringBacktrackingBreadth-First Search
Solve →
148Check if a Parentheses String Can Be ValidMedium
StringStackGreedy
Solve →
149Step-By-Step Directions From a Binary Tree Node to AnotherMedium
StringTreeDepth-First Search
Solve →
150Number of Unique Good SubsequencesHard
StringDynamic Programming
Solve →
151To Lower CaseEasy
String
Solve →
152Minimum Number of Flips to Make the Binary String AlternatingMedium
StringDynamic ProgrammingSliding Window
Solve →
153Longest Happy StringMedium
StringGreedyHeap (Priority Queue)
Solve →
154Delete Characters to Make Fancy StringEasy
String
Solve →
155Cracking the SafeHard
StringDepth-First SearchGraph Theory
Solve →
156Smallest String Starting From LeafMedium
StringBacktrackingTree
Solve →
157Dota2 SenateMedium
StringGreedyQueue
Solve →
158Student Attendance Record IEasy
String
Solve →
159Removing Stars From a StringMedium
StringStackSimulation
Solve →
160Generate Binary Strings Without Adjacent ZerosMedium
StringBacktrackingBit Manipulation
Solve →
161Flip String to Monotone IncreasingMedium
StringDynamic Programming
Solve →
162Minimum Recolors to Get K Consecutive Black BlocksEasy
StringSliding Window
Solve →
163Find the Original Typed String IEasy
String
Solve →
164License Key FormattingEasy
String
Solve →
165Maximum Nesting Depth of the ParenthesesEasy
StringStack
Solve →
166Sorting the SentenceEasy
StringSorting
Solve →
167Minimum Number of Changes to Make Binary String BeautifulMedium
String
Solve →
168Verify Preorder Serialization of a Binary TreeMedium
StringStackTree
Solve →
169Latest Time by Replacing Hidden DigitsEasy
StringGreedy
Solve →
170Jump Game VIIMedium
StringDynamic ProgrammingSliding Window
Solve →
171Minimum String Length After Removing SubstringsEasy
StringStackSimulation
Solve →
172Minimum Insertion Steps to Make a String PalindromeHard
StringDynamic Programming
Solve →
173Maximum Difference Between Even and Odd Frequency IIHard
StringSliding WindowEnumeration
Solve →
174Find the Occurrence of First Almost Equal SubstringHard
StringString Matching
Solve →
175Valid WordEasy
String
Solve →
176Distinct Subsequences IIHard
StringDynamic Programming
Solve →
177Maximum Number of Vowels in a Substring of Given LengthMedium
StringSliding Window
Solve →
178Maximize the Confusion of an ExamMedium
StringBinary SearchSliding Window
Solve →
179Remove Digit From Number to Maximize ResultEasy
StringGreedyEnumeration
Solve →
180Freedom TrailHard
StringDynamic ProgrammingDepth-First Search
Solve →
181Sort Vowels in a StringMedium
StringSorting
Solve →
182Remove All Adjacent Duplicates in String IIMedium
StringStack
Solve →
183Longest Binary Subsequence Less Than or Equal to KMedium
StringDynamic ProgrammingGreedy
Solve →
184Minimum Window SubsequenceHard
StringDynamic ProgrammingSliding Window
Solve →
185Smallest Subsequence of Distinct CharactersMedium
StringStackGreedy
Solve →
186Maximum Repeating SubstringEasy
StringDynamic ProgrammingString Matching
Solve →
187Serialize and Deserialize BSTMedium
StringTreeDepth-First Search
Solve →
188Minimum Penalty for a ShopMedium
StringPrefix Sum
Solve →
189Lexicographically Smallest Equivalent StringMedium
StringUnion-Find
Solve →
190Number of Segments in a StringEasy
String
Solve →
191Special Binary StringHard
StringDivide and ConquerSorting
Solve →
192Maximum Nesting Depth of Two Valid Parentheses StringsMedium
StringStack
Solve →
193Minimum ASCII Delete Sum for Two StringsMedium
StringDynamic Programming
Solve →
194Process String with Special Operations IIHard
StringSimulation
Solve →
195Rearrange Spaces Between WordsEasy
String
Solve →
196Number of Valid Clock TimesEasy
StringEnumeration
Solve →
197Minimum Additions to Make Valid StringMedium
StringDynamic ProgrammingStack
Solve →
198Strange PrinterHard
StringDynamic Programming
Solve →
199Number of Steps to Reduce a Number in Binary Representation to OneMedium
StringBit ManipulationSimulation
Solve →
200Longest Happy PrefixHard
StringRolling HashString Matching
Solve →
201Replace All Digits with CharactersEasy
String
Solve →
202Count Palindromic SubsequencesHard
StringDynamic Programming
Solve →
203Minimum Time to Remove All Cars Containing Illegal GoodsHard
StringDynamic Programming
Solve →
204Count AsterisksEasy
String
Solve →
205Number of Beautiful PartitionsHard
StringDynamic ProgrammingPrefix Sum
Solve →
206Output Contest MatchesMedium
StringRecursionSimulation
Solve →
207Minimum Distance to Type a Word Using Two FingersHard
StringDynamic Programming
Solve →
208Minimum Moves to Convert StringEasy
StringGreedy
Solve →
209Sum of Digits of String After ConvertEasy
StringSimulation
Solve →
210Shortest String That Contains Three StringsMedium
StringGreedyEnumeration
Solve →
211Unique Substrings in Wraparound StringMedium
StringDynamic Programming
Solve →
212Split Array into Fibonacci SequenceMedium
StringBacktracking
Solve →
213Hash Divided StringMedium
StringSimulation
Solve →
214Construct Smallest Number From DI StringMedium
StringBacktrackingStack
Solve →
215Divide a String Into Groups of Size kEasy
StringSimulation
Solve →
216Generate a String With Characters That Have Odd CountsEasy
String
Solve →
217Maximum Product of the Length of Two Palindromic SubsequencesMedium
StringDynamic ProgrammingBacktracking
Solve →
218String Without AAA or BBBMedium
StringGreedy
Solve →
219Count Collisions on a RoadMedium
StringStackSimulation
Solve →
220Brace ExpansionMedium
StringBacktrackingStack
Solve →
221Flip GameEasy
String
Solve →
222Reverse Substrings Between Each Pair of ParenthesesMedium
StringStack
Solve →
223Find Kth Bit in Nth Binary StringMedium
StringRecursionSimulation
Solve →
224Minimum Number of Operations to Convert TimeEasy
StringGreedy
Solve →
225Minimum White Tiles After Covering With CarpetsHard
StringDynamic ProgrammingPrefix Sum
Solve →
226Generalized AbbreviationMedium
StringBacktrackingBit Manipulation
Solve →
227Encode String with Shortest LengthHard
StringDynamic Programming
Solve →
228Longest Uncommon Subsequence IEasy
String
Solve →
229Ambiguous CoordinatesMedium
StringBacktrackingEnumeration
Solve →
230Positions of Large GroupsEasy
String
Solve →
231Occurrences After BigramEasy
String
Solve →
232Iterator for CombinationMedium
StringBacktrackingDesign
Solve →
233Distinct Echo SubstringsHard
StringTrieRolling Hash
Solve →
234Latest Time You Can Obtain After Replacing CharactersEasy
StringEnumeration
Solve →
235Check If String Is Transformable With Substring Sort OperationsHard
StringGreedySorting
Solve →
236Goal Parser InterpretationEasy
String
Solve →
237Find All Good StringsHard
StringDynamic ProgrammingString Matching
Solve →
238Score of ParenthesesMedium
StringStack
Solve →
239Count Substrings That Satisfy K-Constraint IEasy
StringSliding Window
Solve →
240Determine if String Halves Are AlikeEasy
StringCounting
Solve →
241Split a String in Balanced StringsEasy
StringGreedyCounting
Solve →
242Letter Case PermutationMedium
StringBacktrackingBit Manipulation
Solve →
243Minimum Insertions to Balance a Parentheses StringMedium
StringStackGreedy
Solve →
244String Compression IIHard
StringDynamic Programming
Solve →
245Longest Repeating SubstringMedium
StringBinary SearchDynamic Programming
Solve →
246Strong Password CheckerHard
StringGreedyHeap (Priority Queue)
Solve →
247Count Different Palindromic SubsequencesHard
StringDynamic Programming
Solve →
248Validate IP AddressMedium
String
Solve →
249Find Substring With Given Hash ValueHard
StringSliding WindowRolling Hash
Solve →
250Count The Number of Winning SequencesHard
StringDynamic Programming
Solve →
251Count Substrings Divisible By Last DigitHard
StringDynamic Programming
Solve →
252Decrypt String from Alphabet to Integer MappingEasy
String
Solve →
253Zuma GameHard
StringDynamic ProgrammingStack
Solve →
254Masking Personal InformationMedium
String
Solve →
255Valid ParenthesesEasy
StringStack
Solve →
256Generate ParenthesesMedium
StringDynamic ProgrammingBacktracking
Solve →
257Decode StringMedium
StringStackRecursion
Solve →
258Zigzag ConversionMedium
String
Solve →
259Regular Expression MatchingHard
StringDynamic ProgrammingRecursion
Solve →
260Remove K DigitsMedium
StringStackGreedy
Solve →
261Edit DistanceMedium
StringDynamic Programming
Solve →
262Length of Last WordEasy
String
Solve →
263Palindrome PartitioningMedium
StringDynamic ProgrammingBacktracking
Solve →
264Wildcard MatchingHard
StringDynamic ProgrammingGreedy
Solve →
265String to Integer (atoi)Medium
String
Solve →
266Longest Valid ParenthesesHard
StringDynamic ProgrammingStack
Solve →
267Rotate StringEasy
StringString Matching
Solve →
268Longest Common SubsequenceMedium
StringDynamic Programming
Solve →
269Shortest PalindromeHard
StringRolling HashString Matching
Solve →
270Serialize and Deserialize Binary TreeHard
StringTreeDepth-First Search
Solve →
271Lexicographically Smallest Beautiful StringHard
StringGreedy
Solve →
272Simplify PathMedium
StringStack
Solve →
273Repeated Substring PatternEasy
StringString Matching
Solve →
274Remove Duplicate LettersMedium
StringStackGreedy
Solve →
275Remove Outermost ParenthesesEasy
StringStack
Solve →
276Score of a StringEasy
String
Solve →
277Binary Tree PathsEasy
StringBacktrackingTree
Solve →
278Count and SayMedium
String
Solve →
279Repeated String MatchMedium
StringString Matching
Solve →
280Maximum Score After Splitting a StringEasy
StringPrefix Sum
Solve →
281Decode WaysMedium
StringDynamic Programming
Solve →
282Longest Absolute File PathMedium
StringStackDepth-First Search
Solve →
283Detect CapitalEasy
String
Solve →
284Valid Parenthesis StringMedium
StringDynamic ProgrammingStack
Solve →
285Minimum Add to Make Parentheses ValidMedium
StringStackGreedy
Solve →
286Maximum Score From Removing SubstringsMedium
StringStackGreedy
Solve →
287Robot Return to OriginEasy
StringSimulation
Solve →
288Longest Duplicate SubstringHard
StringBinary SearchSliding Window
Solve →
289Make The String GreatEasy
StringStack
Solve →
290Longest Palindromic SubsequenceMedium
StringDynamic Programming
Solve →
291Delete Operation for Two StringsMedium
StringDynamic Programming
Solve →
292Minimum Number of Flips to Make the Binary String AlternatingMedium
StringDynamic ProgrammingSliding Window
Solve →
293Interleaving StringMedium
StringDynamic Programming
Solve →
294Shortest Common SupersequenceHard
StringDynamic Programming
Solve →
295Distinct SubsequencesHard
StringDynamic Programming
Solve →
296Design Search Autocomplete SystemHard
StringDepth-First SearchDesign
Solve →
297Minimum Deletions to Make String BalancedMedium
StringDynamic ProgrammingStack
Solve →
298Flip String to Monotone IncreasingMedium
StringDynamic Programming
Solve →
299Number of Unique Good SubsequencesHard
StringDynamic Programming
Solve →
300Smallest String Starting From LeafMedium
StringBacktrackingTree
Solve →
301Remove All Adjacent Duplicates In StringEasy
StringStack
Solve →
302Defanging an IP AddressEasy
String
Solve →
303Student Attendance Record IEasy
String
Solve →
304Cracking the SafeHard
StringDepth-First SearchGraph Theory
Solve →
305Minimum Remove to Make Valid ParenthesesMedium
StringStack
Solve →
306Minimum Distance to Type a Word Using Two FingersHard
StringDynamic Programming
Solve →
307Jump Game VIIMedium
StringDynamic ProgrammingSliding Window
Solve →
308Design Add and Search Words Data StructureMedium
StringDepth-First SearchDesign
Solve →
309Verify Preorder Serialization of a Binary TreeMedium
StringStackTree
Solve →
310Latest Time by Replacing Hidden DigitsEasy
StringGreedy
Solve →
311License Key FormattingEasy
String
Solve →
312Clear DigitsEasy
StringStackSimulation
Solve →
313Remove All Occurrences of a SubstringMedium
StringStackSimulation
Solve →
314The k-th Lexicographical String of All Happy Strings of Length nMedium
StringBacktracking
Solve →
315Freedom TrailHard
StringDynamic ProgrammingDepth-First Search
Solve →
316Minimum Window SubsequenceHard
StringDynamic ProgrammingSliding Window
Solve →
317Smallest Subsequence of Distinct CharactersMedium
StringStackGreedy
Solve →
318Longest Binary Subsequence Less Than or Equal to KMedium
StringDynamic ProgrammingGreedy
Solve →
319Restore IP AddressesMedium
StringBacktracking
Solve →
320Longest Palindromic Subsequence After at Most K OperationsMedium
StringDynamic Programming
Solve →
321Palindrome Partitioning IIHard
StringDynamic Programming
Solve →
322Output Contest MatchesMedium
StringRecursionSimulation
Solve →
323Distinct Echo SubstringsHard
StringTrieRolling Hash
Solve →
324Longest Happy PrefixHard
StringRolling HashString Matching
Solve →
325Rearrange Spaces Between WordsEasy
String
Solve →
326Minimum Time to Remove All Cars Containing Illegal GoodsHard
StringDynamic Programming
Solve →
327Count AsterisksEasy
String
Solve →
328Number of Beautiful PartitionsHard
StringDynamic ProgrammingPrefix Sum
Solve →
329Number of Valid Clock TimesEasy
StringEnumeration
Solve →
330Parsing A Boolean ExpressionHard
StringStackRecursion
Solve →
331Replace All Digits with CharactersEasy
String
Solve →
332Scramble StringHard
StringDynamic Programming
Solve →
333Flip GameEasy
String
Solve →
334Generalized AbbreviationMedium
StringBacktrackingBit Manipulation
Solve →
335Encode String with Shortest LengthHard
StringDynamic Programming
Solve →
336Longest Uncommon Subsequence IEasy
String
Solve →
337Ambiguous CoordinatesMedium
StringBacktrackingEnumeration
Solve →
338Positions of Large GroupsEasy
String
Solve →
339Brace ExpansionMedium
StringBacktrackingStack
Solve →
340Occurrences After BigramEasy
String
Solve →
341Iterator for CombinationMedium
StringBacktrackingDesign
Solve →
342Check If String Is Transformable With Substring Sort OperationsHard
StringGreedySorting
Solve →
343Minimum White Tiles After Covering With CarpetsHard
StringDynamic ProgrammingPrefix Sum
Solve →
344Minimum Number of Operations to Convert TimeEasy
StringGreedy
Solve →
345Latest Time You Can Obtain After Replacing CharactersEasy
StringEnumeration
Solve →
346Count the Number of Substrings With Dominant OnesMedium
StringEnumeration
Solve →
347Maximum Number of Operations to Move Ones to the EndMedium
StringGreedyCounting
Solve →
348Valid NumberHard
String
Solve →
349Recover a Tree From Preorder TraversalHard
StringTreeDepth-First Search
Solve →
350Serialize and Deserialize N-ary TreeHard
StringTreeDepth-First Search
Solve →
351Special Binary StringHard
StringDivide and ConquerSorting
Solve →
352Find the Original Typed String IIHard
StringDynamic ProgrammingPrefix Sum
Solve →
353Check if a Parentheses String Can Be ValidMedium
StringStackGreedy
Solve →
354Step-By-Step Directions From a Binary Tree Node to AnotherMedium
StringTreeDepth-First Search
Solve →
355Largest 3-Same-Digit Number in StringEasy
String
Solve →
356Additive NumberMedium
StringBacktracking
Solve →
357Longest Happy StringMedium
StringGreedyHeap (Priority Queue)
Solve →
358String Compression IIIMedium
String
Solve →
359Remove Invalid ParenthesesHard
StringBacktrackingBreadth-First Search
Solve →
360Maximum Nesting Depth of the ParenthesesEasy
StringStack
Solve →
361Sorting the SentenceEasy
StringSorting
Solve →
362To Lower CaseEasy
String
Solve →
363Dota2 SenateMedium
StringGreedyQueue
Solve →
364Find Kth Bit in Nth Binary StringMedium
StringRecursionSimulation
Solve →
365Delete Characters to Make Fancy StringEasy
String
Solve →
366Removing Stars From a StringMedium
StringStackSimulation
Solve →
367Generate Binary Strings Without Adjacent ZerosMedium
StringBacktrackingBit Manipulation
Solve →
368Number of Steps to Reduce a Number in Binary Representation to OneMedium
StringBit ManipulationSimulation
Solve →
369Remove All Adjacent Duplicates in String IIMedium
StringStack
Solve →
370Minimum Recolors to Get K Consecutive Black BlocksEasy
StringSliding Window
Solve →
371Find the Original Typed String IEasy
String
Solve →
372Distinct Subsequences IIHard
StringDynamic Programming
Solve →
373Maximize the Confusion of an ExamMedium
StringBinary SearchSliding Window
Solve →
374Minimum Penalty for a ShopMedium
StringPrefix Sum
Solve →
375Sort Vowels in a StringMedium
StringSorting
Solve →
376Minimum String Length After Removing SubstringsEasy
StringStackSimulation
Solve →
377Minimum Number of Changes to Make Binary String BeautifulMedium
String
Solve →
378Minimum Insertion Steps to Make a String PalindromeHard
StringDynamic Programming
Solve →
379Find the Occurrence of First Almost Equal SubstringHard
StringString Matching
Solve →
380Maximum Difference Between Even and Odd Frequency IIHard
StringSliding WindowEnumeration
Solve →
381Valid WordEasy
String
Solve →
382Process String with Special Operations IIHard
StringSimulation
Solve →
383Minimum ASCII Delete Sum for Two StringsMedium
StringDynamic Programming
Solve →
384Maximum Number of Vowels in a Substring of Given LengthMedium
StringSliding Window
Solve →
385Remove Digit From Number to Maximize ResultEasy
StringGreedyEnumeration
Solve →
386Strange PrinterHard
StringDynamic Programming
Solve →
387Score of ParenthesesMedium
StringStack
Solve →
388Number of Segments in a StringEasy
String
Solve →
389Maximum Repeating SubstringEasy
StringDynamic ProgrammingString Matching
Solve →
390Serialize and Deserialize BSTMedium
StringTreeDepth-First Search
Solve →
391String Without AAA or BBBMedium
StringGreedy
Solve →
392Lexicographically Smallest Equivalent StringMedium
StringUnion-Find
Solve →
393Validate IP AddressMedium
String
Solve →
394Maximum Nesting Depth of Two Valid Parentheses StringsMedium
StringStack
Solve →
395Lexicographically Smallest Generated StringHard
StringGreedyString Matching
Solve →
396Count Palindromic SubsequencesHard
StringDynamic Programming
Solve →
397Minimum Additions to Make Valid StringMedium
StringDynamic ProgrammingStack
Solve →
398Strong Password CheckerHard
StringGreedyHeap (Priority Queue)
Solve →
399Minimum Moves to Convert StringEasy
StringGreedy
Solve →
400Sum of Digits of String After ConvertEasy
StringSimulation
Solve →
401Shortest String That Contains Three StringsMedium
StringGreedyEnumeration
Solve →
402Split Array into Fibonacci SequenceMedium
StringBacktracking
Solve →
403Construct Smallest Number From DI StringMedium
StringBacktrackingStack
Solve →
404Hash Divided StringMedium
StringSimulation
Solve →
405Divide a String Into Groups of Size kEasy
StringSimulation
Solve →
406Generate a String With Characters That Have Odd CountsEasy
String
Solve →
407Unique Substrings in Wraparound StringMedium
StringDynamic Programming
Solve →
408Letter Case PermutationMedium
StringBacktrackingBit Manipulation
Solve →
409Maximum Product of the Length of Two Palindromic SubsequencesMedium
StringDynamic ProgrammingBacktracking
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410Count Collisions on a RoadMedium
StringStackSimulation
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411Partitioning Into Minimum Number Of Deci-Binary NumbersMedium
StringGreedy
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412Check if Strings Can be Made Equal With Operations IEasy
String
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413Decode the Slanted CiphertextMedium
StringSimulation
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414Furthest Point From OriginEasy
StringCounting
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415Longest Repeating SubstringMedium
StringBinary SearchDynamic Programming
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416Find All Good StringsHard
StringDynamic ProgrammingString Matching
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417Reverse Substrings Between Each Pair of ParenthesesMedium
StringStack
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418String Compression IIHard
StringDynamic Programming
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419Determine if String Halves Are AlikeEasy
StringCounting
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420Count Substrings That Satisfy K-Constraint IEasy
StringSliding Window
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421Goal Parser InterpretationEasy
String
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422Split a String in Balanced StringsEasy
StringGreedyCounting
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423Minimum Insertions to Balance a Parentheses StringMedium
StringStackGreedy
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424Restore The ArrayHard
StringDynamic Programming
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425Count Different Palindromic SubsequencesHard
StringDynamic Programming
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426Find Substring With Given Hash ValueHard
StringSliding WindowRolling Hash
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427Count The Number of Winning SequencesHard
StringDynamic Programming
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428Zuma GameHard
StringDynamic ProgrammingStack
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429Maximize Active Section with Trade IMedium
StringEnumeration
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430IP to CIDRMedium
StringBit Manipulation
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431Reverse Degree of a StringEasy
StringSimulation
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432Decrypt String from Alphabet to Integer MappingEasy
String
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433Check if Binary String Has at Most One Segment of OnesEasy
String
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434Count Substrings Divisible By Last DigitHard
StringDynamic Programming
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435Count Stepping Numbers in RangeHard
StringDynamic Programming
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436Masking Personal InformationMedium
String
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437Longest Palindromic Path in GraphHard
StringDynamic ProgrammingBit Manipulation
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438Process String with Special Operations IMedium
StringSimulation
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439Longest Substring Of All Vowels in OrderMedium
StringSliding Window
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