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
972. Equal Rational Numbers	Hard	46.7%	Math String	Read
975. Odd Even Jump	Hard	41.1%	Array Dynamic Programming+3	Read
980. Unique Paths III	Hard	82.8%	Array Backtracking+2	Read
982. Triples with Bitwise AND Equal To Zero	Hard	60.1%	Array Bit Manipulation+1	Read
987. Vertical Order Traversal of a Binary Tree	Hard	54.6%	Binary Tree Breadth-First Search+4	Read
992. Subarrays with K Different Integers	Hard	69.0%	Array Counting+2	Read
995. Minimum Number of K Consecutive Bit Flips	Hard	62.7%	Array Bit Manipulation+3	Read
996. Number of Squareful Arrays	Hard	51.9%	Array Backtracking+5	Read
1000. Minimum Cost to Merge Stones	Hard	47.0%	Array Dynamic Programming+1	Read
1001. Grid Illumination	Hard	39.7%	Array Hash Table	Read
1012. Numbers With Repeated Digits	Hard	48.3%	Dynamic Programming Math	Read
1028. Recover a Tree From Preorder Traversal	Hard	83.2%	Binary Tree Depth-First Search+2	Read
1032. Stream of Characters	Hard	52.8%	Array Data Stream+3	Read
1036. Escape a Large Maze	Hard	37.0%	Array Breadth-First Search+2	Read
1044. Longest Duplicate Substring	Hard	31.1%	Binary Search Hash Function+4	Read
1063. Number of Valid Subarrays	Hard	79.9%	Array Monotonic Stack+1	Read
1067. Digit Count in Range	Hard	46.4%	Dynamic Programming Math	Read
1074. Number of Submatrices That Sum to Target	Hard	74.4%	Array Hash Table+2	Read
1088. Confusing Number II	Hard	47.1%	Backtracking Math	Read
1092. Shortest Common Supersequence	Hard	61.8%	Dynamic Programming String	Read
1095. Find in Mountain Array	Hard	41.9%	Array Binary Search+1	Read
1096. Brace Expansion II	Hard	64.0%	Backtracking Breadth-First Search+2	Read
1097. Game Play Analysis V	Hard	50.8%	Database	Read
1106. Parsing A Boolean Expression	Hard	69.8%	Recursion Stack+1	Read
1121. Divide Array Into Increasing Sequences	Hard	65.4%	Array Counting	Read
1125. Smallest Sufficient Team	Hard	55.5%	Array Bit Manipulation+2	Read
1127. User Purchase Platform	Hard	46.9%	Database	Read
1147. Longest Chunked Palindrome Decomposition	Hard	58.6%	Dynamic Programming Greedy+4	Read
1153. String Transforms Into Another String	Hard	34.9%	Hash Table String	Read
1157. Online Majority Element In Subarray	Hard	40.9%	Array Binary Indexed Tree+3	Read
1159. Market Analysis II	Hard	57.4%	Database	Read
1163. Last Substring in Lexicographical Order	Hard	35.1%	String Two Pointers	Read
1168. Optimize Water Distribution in a Village	Hard	65.5%	Graph Heap (Priority Queue)+2	Read
1172. Dinner Plate Stacks	Hard	33.6%	Design Hash Table+2	Read
1178. Number of Valid Words for Each Puzzle	Hard	47.8%	Array Bit Manipulation+3	Read
1183. Maximum Number of Ones	Hard	70.6%	Greedy Heap (Priority Queue)	Read
1187. Make Array Strictly Increasing	Hard	58.0%	Array Binary Search+2	Read
1192. Critical Connections in a Network	Hard	60.6%	Biconnected Component Depth-First Search+1	Read
1194. Tournament Winners	Hard	49.3%	Database	Read
1199. Minimum Time to Build Blocks	Hard	49.2%	Array Greedy+2	Read
1203. Sort Items by Groups Respecting Dependencies	Hard	66.0%	Breadth-First Search Depth-First Search+2	Read
1206. Design Skiplist	Hard	59.7%	Design Linked List	Read
1210. Minimum Moves to Reach Target with Rotations	Hard	52.7%	Array Breadth-First Search+1	Read
1216. Valid Palindrome III	Hard	49.2%	Dynamic Programming String	Read
1220. Count Vowels Permutation	Hard	61.7%	Dynamic Programming	Read
1223. Dice Roll Simulation	Hard	51.4%	Array Dynamic Programming	Read
1224. Maximum Equal Frequency	Hard	38.2%	Array Hash Table	Read
1225. Report Contiguous Dates	Hard	56.9%	Database	Read
1231. Divide Chocolate	Hard	60.5%	Array Binary Search	Read
1235. Maximum Profit in Job Scheduling	Hard	54.8%	Array Binary Search+2	Read

#972Hard

Equal Rational Numbers

MathString

Acceptance: 46.7%

#975Hard

Odd Even Jump

ArrayDynamic ProgrammingMonotonic Stack+2

Acceptance: 41.1%

#980Hard

Unique Paths III

ArrayBacktrackingBit Manipulation+1

Acceptance: 82.8%

#982Hard

Triples with Bitwise AND Equal To Zero

ArrayBit ManipulationHash Table

Acceptance: 60.1%

#987Hard

Vertical Order Traversal of a Binary Tree

Binary TreeBreadth-First SearchDepth-First Search+3

Acceptance: 54.6%

#992Hard

Subarrays with K Different Integers

ArrayCountingHash Table+1

Acceptance: 69.0%

#995Hard

Minimum Number of K Consecutive Bit Flips

ArrayBit ManipulationPrefix Sum+2

Acceptance: 62.7%

#996Hard

Number of Squareful Arrays

ArrayBacktrackingBit Manipulation+4

Acceptance: 51.9%

#1000Hard

Minimum Cost to Merge Stones

ArrayDynamic ProgrammingPrefix Sum

Acceptance: 47.0%

#1001Hard

Grid Illumination

ArrayHash Table

Acceptance: 39.7%

#1012Hard

Numbers With Repeated Digits

Dynamic ProgrammingMath

Acceptance: 48.3%

#1028Hard

Recover a Tree From Preorder Traversal

Binary TreeDepth-First SearchString+1

Acceptance: 83.2%

#1032Hard

Stream of Characters

ArrayData StreamDesign+2

Acceptance: 52.8%

#1036Hard

Escape a Large Maze

ArrayBreadth-First SearchDepth-First Search+1

Acceptance: 37.0%

#1044Hard

Longest Duplicate Substring

Binary SearchHash FunctionRolling Hash+3

Acceptance: 31.1%

#1063Hard

Number of Valid Subarrays

ArrayMonotonic StackStack

Acceptance: 79.9%

#1067Hard

Digit Count in Range

Dynamic ProgrammingMath

Acceptance: 46.4%

#1074Hard

Number of Submatrices That Sum to Target

ArrayHash TableMatrix+1

Acceptance: 74.4%

#1088Hard

Confusing Number II

BacktrackingMath

Acceptance: 47.1%

#1092Hard

Shortest Common Supersequence

Dynamic ProgrammingString

Acceptance: 61.8%

#1095Hard

Find in Mountain Array

ArrayBinary SearchInteractive

Acceptance: 41.9%

#1096Hard

Brace Expansion II

BacktrackingBreadth-First SearchStack+1

Acceptance: 64.0%

#1097Hard

Game Play Analysis V

Database

Acceptance: 50.8%

#1106Hard

Parsing A Boolean Expression

RecursionStackString

Acceptance: 69.8%

#1121Hard

Divide Array Into Increasing Sequences

ArrayCounting

Acceptance: 65.4%

#1125Hard

Smallest Sufficient Team

ArrayBit ManipulationBitmask+1

Acceptance: 55.5%

#1127Hard

User Purchase Platform

Database

Acceptance: 46.9%

#1147Hard

Longest Chunked Palindrome Decomposition

Dynamic ProgrammingGreedyHash Function+3

Acceptance: 58.6%

#1153Hard

String Transforms Into Another String

Hash TableString

Acceptance: 34.9%

#1157Hard

Online Majority Element In Subarray

ArrayBinary Indexed TreeBinary Search+2

Acceptance: 40.9%

#1159Hard

Market Analysis II

Database

Acceptance: 57.4%

#1163Hard

Last Substring in Lexicographical Order

StringTwo Pointers

Acceptance: 35.1%

#1168Hard

Optimize Water Distribution in a Village

GraphHeap (Priority Queue)Minimum Spanning Tree+1

Acceptance: 65.5%

#1172Hard

Dinner Plate Stacks

DesignHash TableHeap (Priority Queue)+1

Acceptance: 33.6%

#1178Hard

Number of Valid Words for Each Puzzle

ArrayBit ManipulationHash Table+2

Acceptance: 47.8%

#1183Hard

Maximum Number of Ones

GreedyHeap (Priority Queue)

Acceptance: 70.6%

#1187Hard

Make Array Strictly Increasing

ArrayBinary SearchDynamic Programming+1

Acceptance: 58.0%

#1192Hard

Critical Connections in a Network

Biconnected ComponentDepth-First SearchGraph

Acceptance: 60.6%

#1194Hard

Tournament Winners

Database

Acceptance: 49.3%

#1199Hard

Minimum Time to Build Blocks

ArrayGreedyHeap (Priority Queue)+1

Acceptance: 49.2%

#1203Hard

Sort Items by Groups Respecting Dependencies

Breadth-First SearchDepth-First SearchGraph+1

Acceptance: 66.0%

#1206Hard

Design Skiplist

DesignLinked List

Acceptance: 59.7%

#1210Hard

Minimum Moves to Reach Target with Rotations

ArrayBreadth-First SearchMatrix

Acceptance: 52.7%

#1216Hard

Valid Palindrome III

Dynamic ProgrammingString

Acceptance: 49.2%

#1220Hard

Count Vowels Permutation

Dynamic Programming

Acceptance: 61.7%

#1223Hard

Dice Roll Simulation

ArrayDynamic Programming

Acceptance: 51.4%

#1224Hard

Maximum Equal Frequency

ArrayHash Table

Acceptance: 38.2%

#1225Hard

Report Contiguous Dates

Database

Acceptance: 56.9%

#1231Hard

Divide Chocolate

ArrayBinary Search

Acceptance: 60.5%

#1235Hard

Maximum Profit in Job Scheduling

ArrayBinary SearchDynamic Programming+1

Acceptance: 54.8%

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