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
3151. Special Array I	Easy	81.6%	Array	Read
3152. Special Array II	Medium	45.8%	Array Binary Search+1	Read
3153. Sum of Digit Differences of All Pairs	Medium	43.3%	Array Counting+2	Read
3154. Find Number of Ways to Reach the K-th Stair	Hard	38.2%	Bit Manipulation Combinatorics+3	Read
3155. Maximum Number of Upgradable Servers	Medium	43.8%	Array Binary Search+1	Read
3156. Employee Task Duration and Concurrent Tasks	Hard	54.0%	Database	Read
3157. Find the Level of Tree with Minimum Sum	Medium	69.6%	Binary Tree Breadth-First Search+2	Read
3158. Find the XOR of Numbers Which Appear Twice	Easy	78.9%	Array Bit Manipulation+1	Read
3159. Find Occurrences of an Element in an Array	Medium	73.6%	Array Hash Table	Read
3160. Find the Number of Distinct Colors Among the Balls	Medium	54.2%	Array Hash Table+1	Read
3161. Block Placement Queries	Hard	41.0%	Array Binary Indexed Tree+2	Read
3162. Find the Number of Good Pairs I	Easy	86.4%	Array Hash Table	Read
3163. String Compression III	Medium	67.0%	String	Read
3164. Find the Number of Good Pairs II	Medium	26.6%	Array Hash Table	Read
3165. Maximum Sum of Subsequence With Non-adjacent Elements	Hard	15.7%	Array Divide and Conquer+2	Read
3166. Calculate Parking Fees and Duration	Medium	53.0%	Database	Read
3167. Better Compression of String	Medium	75.3%	Counting Hash Table+2	Read
3168. Minimum Number of Chairs in a Waiting Room	Easy	79.3%	Simulation String	Read
3169. Count Days Without Meetings	Medium	48.1%	Array Sorting	Read
3170. Lexicographically Minimum String After Removing Stars	Medium	51.0%	Greedy Hash Table+3	Read
3171. Find Subarray With Bitwise OR Closest to K	Hard	31.5%	Array Binary Search+2	Read
3172. Second Day Verification	Easy	70.7%	Database	Read
3173. Bitwise OR of Adjacent Elements	Easy	94.8%	Array Bit Manipulation	Read
3174. Clear Digits	Easy	82.7%	Simulation Stack+1	Read
3175. Find The First Player to win K Games in a Row	Medium	40.1%	Array Simulation	Read
3176. Find the Maximum Length of a Good Subsequence I	Medium	32.6%	Array Dynamic Programming+1	Read
3177. Find the Maximum Length of a Good Subsequence II	Hard	25.2%	Array Dynamic Programming+1	Read
3178. Find the Child Who Has the Ball After K Seconds	Easy	62.3%	Math Simulation	Read
3179. Find the N-th Value After K Seconds	Medium	54.0%	Array Combinatorics+3	Read
3180. Maximum Total Reward Using Operations I	Medium	30.8%	Array Dynamic Programming	Read
3181. Maximum Total Reward Using Operations II	Hard	21.9%	Array Bit Manipulation+1	Read
3182. Find Top Scoring Students	Medium	49.4%	Database	Read
3183. The Number of Ways to Make the Sum	Medium	50.8%	Array Dynamic Programming	Read
3184. Count Pairs That Form a Complete Day I	Easy	78.0%	Array Counting+1	Read
3185. Count Pairs That Form a Complete Day II	Medium	43.7%	Array Counting+1	Read
3186. Maximum Total Damage With Spell Casting	Medium	45.1%	Array Binary Search+5	Read
3187. Peaks in Array	Hard	27.9%	Array Binary Indexed Tree+1	Read
3188. Find Top Scoring Students II	Hard	37.8%	Database	Read
3189. Minimum Moves to Get a Peaceful Board	Medium	75.9%	Array Counting Sort+2	Read
3190. Find Minimum Operations to Make All Elements Divisible by Three	Easy	90.9%	Array Math	Read
3191. Minimum Operations to Make Binary Array Elements Equal to One I	Medium	80.4%	Array Bit Manipulation+3	Read
3192. Minimum Operations to Make Binary Array Elements Equal to One II	Medium	65.1%	Array Dynamic Programming+1	Read
3193. Count the Number of Inversions	Hard	31.9%	Array Dynamic Programming	Read
3194. Minimum Average of Smallest and Largest Elements	Easy	85.4%	Array Sorting+1	Read
3195. Find the Minimum Area to Cover All Ones I	Medium	78.2%	Array Matrix	Read
3196. Maximize Total Cost of Alternating Subarrays	Medium	29.6%	Array Dynamic Programming	Read
3197. Find the Minimum Area to Cover All Ones II	Hard	63.5%	Array Enumeration+1	Read
3198. Find Cities in Each State	Easy	82.5%	Database	Read
3199. Count Triplets with Even XOR Set Bits I	Easy	83.3%	Array Bit Manipulation	Read
3200. Maximum Height of a Triangle	Easy	44.8%	Array Enumeration	Read

#3151Easy

Special Array I

Array

Acceptance: 81.6%

#3152Medium

Special Array II

ArrayBinary SearchPrefix Sum

Acceptance: 45.8%

#3153Medium

Sum of Digit Differences of All Pairs

ArrayCountingHash Table+1

Acceptance: 43.3%

#3154Hard

Find Number of Ways to Reach the K-th Stair

Bit ManipulationCombinatoricsDynamic Programming+2

Acceptance: 38.2%

#3155Medium

Maximum Number of Upgradable Servers

ArrayBinary SearchMath

Acceptance: 43.8%

#3156Hard

Employee Task Duration and Concurrent Tasks

Database

Acceptance: 54.0%

#3157Medium

Find the Level of Tree with Minimum Sum

Binary TreeBreadth-First SearchDepth-First Search+1

Acceptance: 69.6%

#3158Easy

Find the XOR of Numbers Which Appear Twice

ArrayBit ManipulationHash Table

Acceptance: 78.9%

#3159Medium

Find Occurrences of an Element in an Array

ArrayHash Table

Acceptance: 73.6%

#3160Medium

Find the Number of Distinct Colors Among the Balls

ArrayHash TableSimulation

Acceptance: 54.2%

#3161Hard

Block Placement Queries

ArrayBinary Indexed TreeBinary Search+1

Acceptance: 41.0%

#3162Easy

Find the Number of Good Pairs I

ArrayHash Table

Acceptance: 86.4%

#3163Medium

String Compression III

String

Acceptance: 67.0%

#3164Medium

Find the Number of Good Pairs II

ArrayHash Table

Acceptance: 26.6%

#3165Hard

Maximum Sum of Subsequence With Non-adjacent Elements

ArrayDivide and ConquerDynamic Programming+1

Acceptance: 15.7%

#3166Medium

Calculate Parking Fees and Duration

Database

Acceptance: 53.0%

#3167Medium

Better Compression of String

CountingHash TableSorting+1

Acceptance: 75.3%

#3168Easy

Minimum Number of Chairs in a Waiting Room

SimulationString

Acceptance: 79.3%

#3169Medium

Count Days Without Meetings

ArraySorting

Acceptance: 48.1%

#3170Medium

Lexicographically Minimum String After Removing Stars

GreedyHash TableHeap (Priority Queue)+2

Acceptance: 51.0%

#3171Hard

Find Subarray With Bitwise OR Closest to K

ArrayBinary SearchBit Manipulation+1

Acceptance: 31.5%

#3172Easy

Second Day Verification

Database

Acceptance: 70.7%

#3173Easy

Bitwise OR of Adjacent Elements

ArrayBit Manipulation

Acceptance: 94.8%

#3174Easy

Clear Digits

SimulationStackString

Acceptance: 82.7%

#3175Medium

Find The First Player to win K Games in a Row

ArraySimulation

Acceptance: 40.1%

#3176Medium

Find the Maximum Length of a Good Subsequence I

ArrayDynamic ProgrammingHash Table

Acceptance: 32.6%

#3177Hard

Find the Maximum Length of a Good Subsequence II

ArrayDynamic ProgrammingHash Table

Acceptance: 25.2%

#3178Easy

Find the Child Who Has the Ball After K Seconds

MathSimulation

Acceptance: 62.3%

#3179Medium

Find the N-th Value After K Seconds

ArrayCombinatoricsMath+2

Acceptance: 54.0%

#3180Medium

Maximum Total Reward Using Operations I

ArrayDynamic Programming

Acceptance: 30.8%

#3181Hard

Maximum Total Reward Using Operations II

ArrayBit ManipulationDynamic Programming

Acceptance: 21.9%

#3182Medium

Find Top Scoring Students

Database

Acceptance: 49.4%

#3183Medium

The Number of Ways to Make the Sum

ArrayDynamic Programming

Acceptance: 50.8%

#3184Easy

Count Pairs That Form a Complete Day I

ArrayCountingHash Table

Acceptance: 78.0%

#3185Medium

Count Pairs That Form a Complete Day II

ArrayCountingHash Table

Acceptance: 43.7%

#3186Medium

Maximum Total Damage With Spell Casting

ArrayBinary SearchCounting+4

Acceptance: 45.1%

#3187Hard

Peaks in Array

ArrayBinary Indexed TreeSegment Tree

Acceptance: 27.9%

#3188Hard

Find Top Scoring Students II

Database

Acceptance: 37.8%

#3189Medium

Minimum Moves to Get a Peaceful Board

ArrayCounting SortGreedy+1

Acceptance: 75.9%

#3190Easy

Find Minimum Operations to Make All Elements Divisible by Three

ArrayMath

Acceptance: 90.9%

#3191Medium

Minimum Operations to Make Binary Array Elements Equal to One I

ArrayBit ManipulationPrefix Sum+2

Acceptance: 80.4%

#3192Medium

Minimum Operations to Make Binary Array Elements Equal to One II

ArrayDynamic ProgrammingGreedy

Acceptance: 65.1%

#3193Hard

Count the Number of Inversions

ArrayDynamic Programming

Acceptance: 31.9%

#3194Easy

Minimum Average of Smallest and Largest Elements

ArraySortingTwo Pointers

Acceptance: 85.4%

#3195Medium

Find the Minimum Area to Cover All Ones I

ArrayMatrix

Acceptance: 78.2%

#3196Medium

Maximize Total Cost of Alternating Subarrays

ArrayDynamic Programming

Acceptance: 29.6%

#3197Hard

Find the Minimum Area to Cover All Ones II

ArrayEnumerationMatrix

Acceptance: 63.5%

#3198Easy

Find Cities in Each State

Database

Acceptance: 82.5%

#3199Easy

Count Triplets with Even XOR Set Bits I

ArrayBit Manipulation

Acceptance: 83.3%

#3200Easy

Maximum Height of a Triangle

ArrayEnumeration

Acceptance: 44.8%

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