Solutions & Explanations

Browse 4,030+ detailed solutions with multiple approaches, code in Python, Java, C++ and more.

4,030 Solutions961 Easy2102 Medium967 Hard

Title	Difficulty	Acceptance	Topics	Solution
1201. Ugly Number III	Medium	31.9%	Binary Search Combinatorics+2	Read
1202. Smallest String With Swaps	Medium	61.0%	Array Breadth-First Search+5	Read
1203. Sort Items by Groups Respecting Dependencies	Hard	66.0%	Breadth-First Search Depth-First Search+2	Read
1204. Last Person to Fit in the Bus	Medium	68.0%	Database	Read
1205. Monthly Transactions II	Medium	41.8%	Database	Read
1206. Design Skiplist	Hard	59.7%	Design Linked List	Read
1207. Unique Number of Occurrences	Easy	78.7%	Array Hash Table	Read
1208. Get Equal Substrings Within Budget	Medium	60.2%	Binary Search Prefix Sum+2	Read
1209. Remove All Adjacent Duplicates in String II	Medium	61.7%	Stack String	Read
1210. Minimum Moves to Reach Target with Rotations	Hard	52.7%	Array Breadth-First Search+1	Read
1211. Queries Quality and Percentage	Easy	43.6%	Database	Read
1212. Team Scores in Football Tournament	Medium	55.6%	Database	Read
1213. Intersection of Three Sorted Arrays	Easy	80.2%	Array Binary Search+2	Read
1214. Two Sum BSTs	Medium	68.2%	Binary Search Binary Search Tree+5	Read
1215. Stepping Numbers	Medium	48.2%	Backtracking Breadth-First Search+1	Read
1216. Valid Palindrome III	Hard	49.2%	Dynamic Programming String	Read
1217. Minimum Cost to Move Chips to The Same Position	Easy	72.8%	Array Greedy+1	Read
1218. Longest Arithmetic Subsequence of Given Difference	Medium	54.5%	Array Dynamic Programming+1	Read
1219. Path with Maximum Gold	Medium	68.6%	Array Backtracking+1	Read
1220. Count Vowels Permutation	Hard	61.7%	Dynamic Programming	Read
1221. Split a String in Balanced Strings	Easy	87.3%	Counting Greedy+1	Read
1222. Queens That Can Attack the King	Medium	72.6%	Array Matrix+1	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
1226. The Dining Philosophers	Medium	54.5%	Concurrency	Read
1227. Airplane Seat Assignment Probability	Medium	67.3%	Brainteaser Dynamic Programming+2	Read
1228. Missing Number In Arithmetic Progression	Easy	52.0%	Array Math	Read
1229. Meeting Scheduler	Medium	55.3%	Array Sorting+1	Read
1230. Toss Strange Coins	Medium	58.1%	Array Dynamic Programming+2	Read
1231. Divide Chocolate	Hard	60.5%	Array Binary Search	Read
1232. Check If It Is a Straight Line	Easy	40.1%	Array Geometry+1	Read
1233. Remove Sub-Folders from the Filesystem	Medium	78.6%	Array Depth-First Search+2	Read
1234. Replace the Substring for Balanced String	Medium	41.3%	Sliding Window String	Read
1235. Maximum Profit in Job Scheduling	Hard	54.8%	Array Binary Search+2	Read
1236. Web Crawler	Medium	68.8%	Breadth-First Search Depth-First Search+2	Read
1237. Find Positive Integer Solution for a Given Equation	Medium	69.7%	Binary Search Interactive+2	Read
1238. Circular Permutation in Binary Representation	Medium	72.6%	Backtracking Bit Manipulation+1	Read
1239. Maximum Length of a Concatenated String with Unique Characters	Medium	54.7%	Array Backtracking+2	Read
1240. Tiling a Rectangle with the Fewest Squares	Hard	55.0%	Backtracking	Read
1241. Number of Comments per Post	Easy	66.0%	Database	Read
1242. Web Crawler Multithreaded	Medium	49.5%	Breadth-First Search Concurrency+1	Read
1243. Array Transformation	Easy	53.6%	Array Simulation	Read
1244. Design A Leaderboard	Medium	67.9%	Design Hash Table+1	Read
1245. Tree Diameter	Medium	61.1%	Breadth-First Search Depth-First Search+3	Read
1246. Palindrome Removal	Hard	46.4%	Array Dynamic Programming	Read
1247. Minimum Swaps to Make Strings Equal	Medium	65.3%	Greedy Math+1	Read
1248. Count Number of Nice Subarrays	Medium	75.5%	Array Hash Table+3	Read
1249. Minimum Remove to Make Valid Parentheses	Medium	71.3%	Stack String	Read
1250. Check If It Is a Good Array	Hard	65.6%	Array Math+1	Read

#1201Medium

Ugly Number III

Binary SearchCombinatoricsMath+1

Acceptance: 31.9%

#1202Medium

Smallest String With Swaps

ArrayBreadth-First SearchDepth-First Search+4

Acceptance: 61.0%

#1203Hard

Sort Items by Groups Respecting Dependencies

Breadth-First SearchDepth-First SearchGraph+1

Acceptance: 66.0%

#1204Medium

Last Person to Fit in the Bus

Database

Acceptance: 68.0%

#1205Medium

Monthly Transactions II

Database

Acceptance: 41.8%

#1206Hard

Design Skiplist

DesignLinked List

Acceptance: 59.7%

#1207Easy

Unique Number of Occurrences

ArrayHash Table

Acceptance: 78.7%

#1208Medium

Get Equal Substrings Within Budget

Binary SearchPrefix SumSliding Window+1

Acceptance: 60.2%

#1209Medium

Remove All Adjacent Duplicates in String II

StackString

Acceptance: 61.7%

#1210Hard

Minimum Moves to Reach Target with Rotations

ArrayBreadth-First SearchMatrix

Acceptance: 52.7%

#1211Easy

Queries Quality and Percentage

Database

Acceptance: 43.6%

#1212Medium

Team Scores in Football Tournament

Database

Acceptance: 55.6%

#1213Easy

Intersection of Three Sorted Arrays

ArrayBinary SearchCounting+1

Acceptance: 80.2%

#1214Medium

Two Sum BSTs

Binary SearchBinary Search TreeBinary Tree+4

Acceptance: 68.2%

#1215Medium

Stepping Numbers

BacktrackingBreadth-First SearchMath

Acceptance: 48.2%

#1216Hard

Valid Palindrome III

Dynamic ProgrammingString

Acceptance: 49.2%

#1217Easy

Minimum Cost to Move Chips to The Same Position

ArrayGreedyMath

Acceptance: 72.8%

#1218Medium

Longest Arithmetic Subsequence of Given Difference

ArrayDynamic ProgrammingHash Table

Acceptance: 54.5%

#1219Medium

Path with Maximum Gold

ArrayBacktrackingMatrix

Acceptance: 68.6%

#1220Hard

Count Vowels Permutation

Dynamic Programming

Acceptance: 61.7%

#1221Easy

Split a String in Balanced Strings

CountingGreedyString

Acceptance: 87.3%

#1222Medium

Queens That Can Attack the King

ArrayMatrixSimulation

Acceptance: 72.6%

#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%

#1226Medium

The Dining Philosophers

Concurrency

Acceptance: 54.5%

#1227Medium

Airplane Seat Assignment Probability

BrainteaserDynamic ProgrammingMath+1

Acceptance: 67.3%

#1228Easy

Missing Number In Arithmetic Progression

ArrayMath

Acceptance: 52.0%

#1229Medium

Meeting Scheduler

ArraySortingTwo Pointers

Acceptance: 55.3%

#1230Medium

Toss Strange Coins

ArrayDynamic ProgrammingMath+1

Acceptance: 58.1%

#1231Hard

Divide Chocolate

ArrayBinary Search

Acceptance: 60.5%

#1232Easy

Check If It Is a Straight Line

ArrayGeometryMath

Acceptance: 40.1%

#1233Medium

Remove Sub-Folders from the Filesystem

ArrayDepth-First SearchString+1

Acceptance: 78.6%

#1234Medium

Replace the Substring for Balanced String

Sliding WindowString

Acceptance: 41.3%

#1235Hard

Maximum Profit in Job Scheduling

ArrayBinary SearchDynamic Programming+1

Acceptance: 54.8%

#1236Medium

Web Crawler

Breadth-First SearchDepth-First SearchInteractive+1

Acceptance: 68.8%

#1237Medium

Find Positive Integer Solution for a Given Equation

Binary SearchInteractiveMath+1

Acceptance: 69.7%

#1238Medium

Circular Permutation in Binary Representation

BacktrackingBit ManipulationMath

Acceptance: 72.6%

#1239Medium

Maximum Length of a Concatenated String with Unique Characters

ArrayBacktrackingBit Manipulation+1

Acceptance: 54.7%

#1240Hard

Tiling a Rectangle with the Fewest Squares

Backtracking

Acceptance: 55.0%

#1241Easy

Number of Comments per Post

Database

Acceptance: 66.0%

#1242Medium

Web Crawler Multithreaded

Breadth-First SearchConcurrencyDepth-First Search

Acceptance: 49.5%

#1243Easy

Array Transformation

ArraySimulation

Acceptance: 53.6%

#1244Medium

Design A Leaderboard

DesignHash TableSorting

Acceptance: 67.9%

#1245Medium

Tree Diameter

Breadth-First SearchDepth-First SearchGraph+2

Acceptance: 61.1%

#1246Hard

Palindrome Removal

ArrayDynamic Programming

Acceptance: 46.4%

#1247Medium

Minimum Swaps to Make Strings Equal

GreedyMathString

Acceptance: 65.3%

#1248Medium

Count Number of Nice Subarrays

ArrayHash TableMath+2

Acceptance: 75.5%

#1249Medium

Minimum Remove to Make Valid Parentheses

StackString

Acceptance: 71.3%

#1250Hard

Check If It Is a Good Array

ArrayMathNumber Theory

Acceptance: 65.6%

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