Solutions & Explanations

Browse 4,029+ detailed solutions with multiple approaches, code in Python, Java, C++ and more.

4,029 Solutions961 Easy2102 Medium966 Hard

Title	Difficulty	Acceptance	Topics	Solution
901. Online Stock Span	Medium	69.5%	Data Stream Design+2	Read
902. Numbers At Most N Given Digit Set	Hard	45.9%	Array Binary Search+3	Read
903. Valid Permutations for DI Sequence	Hard	56.3%	Dynamic Programming Prefix Sum+1	Read
904. Fruit Into Baskets	Medium	52.5%	Array Hash Table+1	Read
905. Sort Array By Parity	Easy	76.2%	Array Sorting+1	Read
906. Super Palindromes	Hard	39.9%	Enumeration Math	Read
907. Sum of Subarray Minimums	Medium	39.0%	Array Dynamic Programming+2	Read
908. Smallest Range I	Easy	74.0%	Array Math	Read
909. Snakes and Ladders	Medium	48.0%	Array Breadth-First Search+1	Read
910. Smallest Range II	Medium	37.8%	Array Greedy+2	Read
911. Online Election	Medium	52.8%	Array Binary Search+2	Read
912. Sort an Array	Medium	55.9%	Array Bucket Sort+6	Read
913. Cat and Mouse	Hard	36.2%	Dynamic Programming Game Theory+4	Read
914. X of a Kind in a Deck of Cards	Easy	30.4%	Array Counting+3	Read
915. Partition Array into Disjoint Intervals	Medium	49.4%	Array	Read
916. Word Subsets	Medium	55.9%	Array Hash Table+1	Read
917. Reverse Only Letters	Easy	68.9%	String Two Pointers	Read
918. Maximum Sum Circular Subarray	Medium	51.5%	Array Divide and Conquer+3	Read
919. Complete Binary Tree Inserter	Medium	65.0%	Binary Tree Breadth-First Search+2	Read
920. Number of Music Playlists	Hard	60.3%	Combinatorics Dynamic Programming+1	Read
921. Minimum Add to Make Parentheses Valid	Medium	74.7%	Greedy Stack+1	Read
922. Sort Array By Parity II	Easy	71.4%	Array Sorting+1	Read
923. 3Sum With Multiplicity	Medium	46.2%	Array Counting+3	Read
924. Minimize Malware Spread	Hard	43.0%	Array Breadth-First Search+4	Read
925. Long Pressed Name	Easy	32.8%	String Two Pointers	Read
926. Flip String to Monotone Increasing	Medium	61.5%	Dynamic Programming String	Read
927. Three Equal Parts	Hard	41.3%	Array Math	Read
928. Minimize Malware Spread II	Hard	46.2%	Array Breadth-First Search+4	Read
929. Unique Email Addresses	Easy	67.9%	Array Hash Table+1	Read
930. Binary Subarrays With Sum	Medium	69.7%	Array Hash Table+2	Read
931. Minimum Falling Path Sum	Medium	60.8%	Array Dynamic Programming+1	Read
932. Beautiful Array	Medium	70.1%	Array Divide and Conquer+1	Read
933. Number of Recent Calls	Easy	78.9%	Data Stream Design+1	Read
934. Shortest Bridge	Medium	59.3%	Array Breadth-First Search+2	Read
935. Knight Dialer	Medium	61.8%	Dynamic Programming	Read
936. Stamping The Sequence	Hard	62.2%	Greedy Queue+2	Read
937. Reorder Data in Log Files	Medium	56.6%	Array Sorting+1	Read
938. Range Sum of BST	Easy	87.2%	Binary Search Tree Binary Tree+2	Read
939. Minimum Area Rectangle	Medium	55.4%	Array Geometry+3	Read
940. Distinct Subsequences II	Hard	56.7%	Dynamic Programming String	Read
941. Valid Mountain Array	Easy	35.7%	Array	Read
942. DI String Match	Easy	81.0%	Array Greedy+2	Read
943. Find the Shortest Superstring	Hard	45.8%	Array Bit Manipulation+3	Read
944. Delete Columns to Make Sorted	Easy	78.1%	Array String	Read
945. Minimum Increment to Make Array Unique	Medium	60.7%	Array Counting+2	Read
946. Validate Stack Sequences	Medium	70.8%	Array Simulation+1	Read
947. Most Stones Removed with Same Row or Column	Medium	63.4%	Depth-First Search Graph+2	Read
948. Bag of Tokens	Medium	59.5%	Array Greedy+2	Read
949. Largest Time for Given Digits	Medium	36.0%	Array Enumeration+1	Read
950. Reveal Cards In Increasing Order	Medium	83.6%	Array Queue+2	Read

#901Medium

Online Stock Span

Data StreamDesignMonotonic Stack+1

Acceptance: 69.5%

#902Hard

Numbers At Most N Given Digit Set

ArrayBinary SearchDynamic Programming+2

Acceptance: 45.9%

#903Hard

Valid Permutations for DI Sequence

Dynamic ProgrammingPrefix SumString

Acceptance: 56.3%

#904Medium

Fruit Into Baskets

ArrayHash TableSliding Window

Acceptance: 52.5%

#905Easy

Sort Array By Parity

ArraySortingTwo Pointers

Acceptance: 76.2%

#906Hard

Super Palindromes

EnumerationMath

Acceptance: 39.9%

#907Medium

Sum of Subarray Minimums

ArrayDynamic ProgrammingMonotonic Stack+1

Acceptance: 39.0%

#908Easy

Smallest Range I

ArrayMath

Acceptance: 74.0%

#909Medium

Snakes and Ladders

ArrayBreadth-First SearchMatrix

Acceptance: 48.0%

#910Medium

Smallest Range II

ArrayGreedyMath+1

Acceptance: 37.8%

#911Medium

Online Election

ArrayBinary SearchDesign+1

Acceptance: 52.8%

#912Medium

Sort an Array

ArrayBucket SortCounting Sort+5

Acceptance: 55.9%

#913Hard

Cat and Mouse

Dynamic ProgrammingGame TheoryGraph+3

Acceptance: 36.2%

#914Easy

X of a Kind in a Deck of Cards

ArrayCountingHash Table+2

Acceptance: 30.4%

#915Medium

Partition Array into Disjoint Intervals

Array

Acceptance: 49.4%

#916Medium

Word Subsets

ArrayHash TableString

Acceptance: 55.9%

#917Easy

Reverse Only Letters

StringTwo Pointers

Acceptance: 68.9%

#918Medium

Maximum Sum Circular Subarray

ArrayDivide and ConquerDynamic Programming+2

Acceptance: 51.5%

#919Medium

Complete Binary Tree Inserter

Binary TreeBreadth-First SearchDesign+1

Acceptance: 65.0%

#920Hard

Number of Music Playlists

CombinatoricsDynamic ProgrammingMath

Acceptance: 60.3%

#921Medium

Minimum Add to Make Parentheses Valid

GreedyStackString

Acceptance: 74.7%

#922Easy

Sort Array By Parity II

ArraySortingTwo Pointers

Acceptance: 71.4%

#923Medium

3Sum With Multiplicity

ArrayCountingHash Table+2

Acceptance: 46.2%

#924Hard

Minimize Malware Spread

ArrayBreadth-First SearchDepth-First Search+3

Acceptance: 43.0%

#925Easy

Long Pressed Name

StringTwo Pointers

Acceptance: 32.8%

#926Medium

Flip String to Monotone Increasing

Dynamic ProgrammingString

Acceptance: 61.5%

#927Hard

Three Equal Parts

ArrayMath

Acceptance: 41.3%

#928Hard

Minimize Malware Spread II

ArrayBreadth-First SearchDepth-First Search+3

Acceptance: 46.2%

#929Easy

Unique Email Addresses

ArrayHash TableString

Acceptance: 67.9%

#930Medium

Binary Subarrays With Sum

ArrayHash TablePrefix Sum+1

Acceptance: 69.7%

#931Medium

Minimum Falling Path Sum

ArrayDynamic ProgrammingMatrix

Acceptance: 60.8%

#932Medium

Beautiful Array

ArrayDivide and ConquerMath

Acceptance: 70.1%

#933Easy

Number of Recent Calls

Data StreamDesignQueue

Acceptance: 78.9%

#934Medium

Shortest Bridge

ArrayBreadth-First SearchDepth-First Search+1

Acceptance: 59.3%

#935Medium

Knight Dialer

Dynamic Programming

Acceptance: 61.8%

#936Hard

Stamping The Sequence

GreedyQueueStack+1

Acceptance: 62.2%

#937Medium

Reorder Data in Log Files

ArraySortingString

Acceptance: 56.6%

#938Easy

Range Sum of BST

Binary Search TreeBinary TreeDepth-First Search+1

Acceptance: 87.2%

#939Medium

Minimum Area Rectangle

ArrayGeometryHash Table+2

Acceptance: 55.4%

#940Hard

Distinct Subsequences II

Dynamic ProgrammingString

Acceptance: 56.7%

#941Easy

Valid Mountain Array

Array

Acceptance: 35.7%

#942Easy

DI String Match

ArrayGreedyString+1

Acceptance: 81.0%

#943Hard

Find the Shortest Superstring

ArrayBit ManipulationBitmask+2

Acceptance: 45.8%

#944Easy

Delete Columns to Make Sorted

ArrayString

Acceptance: 78.1%

#945Medium

Minimum Increment to Make Array Unique

ArrayCountingGreedy+1

Acceptance: 60.7%

#946Medium

Validate Stack Sequences

ArraySimulationStack

Acceptance: 70.8%

#947Medium

Most Stones Removed with Same Row or Column

Depth-First SearchGraphHash Table+1

Acceptance: 63.4%

#948Medium

Bag of Tokens

ArrayGreedySorting+1

Acceptance: 59.5%

#949Medium

Largest Time for Given Digits

ArrayEnumerationString

Acceptance: 36.0%

#950Medium

Reveal Cards In Increasing Order

ArrayQueueSimulation+1

Acceptance: 83.6%

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