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
3351. Sum of Good Subsequences	Hard	30.9%	Array Dynamic Programming+1	Read
3352. Count K-Reducible Numbers Less Than N	Hard	27.8%	Combinatorics Dynamic Programming+2	Read
3353. Minimum Total Operations	Easy	63.8%	Array	Read
3354. Make Array Elements Equal to Zero	Easy	68.3%	Array Prefix Sum+1	Read
3355. Zero Array Transformation I	Medium	54.5%	Array Prefix Sum	Read
3356. Zero Array Transformation II	Medium	43.6%	Array Binary Search+1	Read
3357. Minimize the Maximum Adjacent Element Difference	Hard	20.2%	Array Binary Search+1	Read
3358. Books with NULL Ratings	Easy	89.4%	Database	Read
3359. Find Sorted Submatrices With Maximum Element at Most K	Hard	51.9%	Array Matrix+2	Read
3360. Stone Removal Game	Easy	43.0%	Math Simulation	Read
3361. Shift Distance Between Two Strings	Medium	52.8%	Array Prefix Sum+1	Read
3362. Zero Array Transformation III	Medium	54.9%	Array Greedy+3	Read
3363. Find the Maximum Number of Fruits Collected	Hard	65.1%	Array Dynamic Programming+1	Read
3364. Minimum Positive Sum Subarray	Easy	45.6%	Array Prefix Sum+1	Read
3365. Rearrange K Substrings to Form Target String	Medium	56.7%	Hash Table Sorting+1	Read
3366. Minimum Array Sum	Medium	31.7%	Array Dynamic Programming	Read
3367. Maximize Sum of Weights after Edge Removals	Hard	31.9%	Depth-First Search Dynamic Programming+2	Read
3368. First Letter Capitalization	Hard	87.7%	Database	Read
3369. Design an Array Statistics Tracker	Hard	35.7%	Binary Search Hash Table+1	Read
3370. Smallest Number With All Set Bits	Easy	80.4%	Bit Manipulation Math	Read
3371. Identify the Largest Outlier in an Array	Medium	36.2%	Array Counting+2	Read
3372. Maximize the Number of Target Nodes After Connecting Trees I	Medium	69.5%	Breadth-First Search Depth-First Search+1	Read
3373. Maximize the Number of Target Nodes After Connecting Trees II	Hard	72.5%	Breadth-First Search Depth-First Search+1	Read
3374. First Letter Capitalization II	Hard	90.0%	Database	Read
3874. Valid Subarrays With Exactly One Peak	Medium	66.9%		Read
3865. Reverse K Subarrays	Medium	88.6%	Array Two Pointers	Read
3876. Construct Uniform Parity Array II	Medium	66.3%	Array Math	Read
3875. Construct Uniform Parity Array I	Easy	85.8%	Array Math	Read
3868. Minimum Cost to Equalize Arrays Using Swaps	Medium	48.7%	Array Counting+2	Read
3866. First Unique Even Element	Easy	65.6%	Array Counting+1	Read
3851. Maximum Requests Without Violating the Limit	Medium	63.5%	Array Greedy+3	Read
3873. Maximum Points Activated with One Addition	Hard	42.8%	Array Hash Table+1	Read
3871. Count Commas in Range II	Medium	49.3%	Math	Read
3861. Minimum Capacity Box	Easy	72.8%	Array	Read
3870. Count Commas in Range	Easy	78.0%	Math	Read
3867. Sum of GCD of Formed Pairs	Medium	75.1%	Array Math+3	Read
3860. Unique Email Groups	Medium	84.8%	Array Hash Table+1	Read
3862. Find the Smallest Balanced Index	Medium	19.2%	Array Prefix Sum	Read
3855. Sum of K-Digit Numbers in a Range	Hard	50.5%	Combinatorics Divide and Conquer+2	Read
3852. Smallest Pair With Different Frequencies	Easy	68.5%	Array Counting+1	Read
3872. Longest Arithmetic Sequence After Changing At Most One Element	Medium	21.4%	Array Enumeration	Read
3856. Trim Trailing Vowels	Easy	77.2%	String	Read
3837. Delayed Count of Equal Elements	Medium	78.3%	Array Counting+1	Read
3848. Check Digitorial Permutation	Medium	46.5%	Counting Math	Read
3847. Find the Score Difference in a Game	Medium	72.7%	Array Simulation	Read
3878. Count Good Subarrays	Hard	25.6%	Array Bit Manipulation+2	Read
3844. Longest Almost-Palindromic Substring	Medium	22.8%	Dynamic Programming String+1	Read
3863. Minimum Operations to Sort a String	Medium	19.1%	String	Read
3854. Minimum Operations to Make Array Parity Alternating	Medium	17.1%	Array Greedy	Read
3843. First Element with Unique Frequency	Medium	69.9%	Array Counting+1	Read

#3351Hard

Sum of Good Subsequences

ArrayDynamic ProgrammingHash Table

Acceptance: 30.9%

#3352Hard

Count K-Reducible Numbers Less Than N

CombinatoricsDynamic ProgrammingMath+1

Acceptance: 27.8%

#3353Easy

Minimum Total Operations

Array

Acceptance: 63.8%

#3354Easy

Make Array Elements Equal to Zero

ArrayPrefix SumSimulation

Acceptance: 68.3%

#3355Medium

Zero Array Transformation I

ArrayPrefix Sum

Acceptance: 54.5%

#3356Medium

Zero Array Transformation II

ArrayBinary SearchPrefix Sum

Acceptance: 43.6%

#3357Hard

Minimize the Maximum Adjacent Element Difference

ArrayBinary SearchGreedy

Acceptance: 20.2%

#3358Easy

Books with NULL Ratings

Database

Acceptance: 89.4%

#3359Hard

Find Sorted Submatrices With Maximum Element at Most K

ArrayMatrixMonotonic Stack+1

Acceptance: 51.9%

#3360Easy

Stone Removal Game

MathSimulation

Acceptance: 43.0%

#3361Medium

Shift Distance Between Two Strings

ArrayPrefix SumString

Acceptance: 52.8%

#3362Medium

Zero Array Transformation III

ArrayGreedyHeap (Priority Queue)+2

Acceptance: 54.9%

#3363Hard

Find the Maximum Number of Fruits Collected

ArrayDynamic ProgrammingMatrix

Acceptance: 65.1%

#3364Easy

Minimum Positive Sum Subarray

ArrayPrefix SumSliding Window

Acceptance: 45.6%

#3365Medium

Rearrange K Substrings to Form Target String

Hash TableSortingString

Acceptance: 56.7%

#3366Medium

Minimum Array Sum

ArrayDynamic Programming

Acceptance: 31.7%

#3367Hard

Maximize Sum of Weights after Edge Removals

Depth-First SearchDynamic ProgrammingSorting+1

Acceptance: 31.9%

#3368Hard

First Letter Capitalization

Database

Acceptance: 87.7%

#3369Hard

Design an Array Statistics Tracker

Binary SearchHash TableQueue

Acceptance: 35.7%

#3370Easy

Smallest Number With All Set Bits

Bit ManipulationMath

Acceptance: 80.4%

#3371Medium

Identify the Largest Outlier in an Array

ArrayCountingEnumeration+1

Acceptance: 36.2%

#3372Medium

Maximize the Number of Target Nodes After Connecting Trees I

Breadth-First SearchDepth-First SearchTree

Acceptance: 69.5%

#3373Hard

Maximize the Number of Target Nodes After Connecting Trees II

Breadth-First SearchDepth-First SearchTree

Acceptance: 72.5%

#3374Hard

First Letter Capitalization II

Database

Acceptance: 90.0%

#3874Medium

Valid Subarrays With Exactly One Peak

Acceptance: 66.9%

#3865Medium

Reverse K Subarrays

ArrayTwo Pointers

Acceptance: 88.6%

#3876Medium

Construct Uniform Parity Array II

ArrayMath

Acceptance: 66.3%

#3875Easy

Construct Uniform Parity Array I

ArrayMath

Acceptance: 85.8%

#3868Medium

Minimum Cost to Equalize Arrays Using Swaps

ArrayCountingGreedy+1

Acceptance: 48.7%

#3866Easy

First Unique Even Element

ArrayCountingHash Table

Acceptance: 65.6%

#3851Medium

Maximum Requests Without Violating the Limit

ArrayGreedyHash Table+2

Acceptance: 63.5%

#3873Hard

Maximum Points Activated with One Addition

ArrayHash TableUnion Find

Acceptance: 42.8%

#3871Medium

Count Commas in Range II

Math

Acceptance: 49.3%

#3861Easy

Minimum Capacity Box

Array

Acceptance: 72.8%

#3870Easy

Count Commas in Range

Math

Acceptance: 78.0%

#3867Medium

Sum of GCD of Formed Pairs

ArrayMathNumber Theory+2

Acceptance: 75.1%

#3860Medium

Unique Email Groups

ArrayHash TableString

Acceptance: 84.8%

#3862Medium

Find the Smallest Balanced Index

ArrayPrefix Sum

Acceptance: 19.2%

#3855Hard

Sum of K-Digit Numbers in a Range

CombinatoricsDivide and ConquerMath+1

Acceptance: 50.5%

#3852Easy

Smallest Pair With Different Frequencies

ArrayCountingHash Table

Acceptance: 68.5%

#3872Medium

Longest Arithmetic Sequence After Changing At Most One Element

ArrayEnumeration

Acceptance: 21.4%

#3856Easy

Trim Trailing Vowels

String

Acceptance: 77.2%

#3837Medium

Delayed Count of Equal Elements

ArrayCountingHash Table

Acceptance: 78.3%

#3848Medium

Check Digitorial Permutation

CountingMath

Acceptance: 46.5%

#3847Medium

Find the Score Difference in a Game

ArraySimulation

Acceptance: 72.7%

#3878Hard

Count Good Subarrays

ArrayBit ManipulationMonotonic Stack+1

Acceptance: 25.6%

#3844Medium

Longest Almost-Palindromic Substring

Dynamic ProgrammingStringTwo Pointers

Acceptance: 22.8%

#3863Medium

Minimum Operations to Sort a String

String

Acceptance: 19.1%

#3854Medium

Minimum Operations to Make Array Parity Alternating

ArrayGreedy

Acceptance: 17.1%

#3843Medium

First Element with Unique Frequency

ArrayCountingHash Table

Acceptance: 69.9%

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